Statistics Questions

A student study of the effects of caffeine asked volunteers to take a memory test 2 hours after drinking soda Some drank caffeine free some drank regular and others drank a mixture of the two getting a half dose of caffeine The 5 number summaries for each group s scores number of items recalled correctly on the memory test are shown below Complete parts a through d No Caffeine Low Caffeine High Caffeine 15 Who What Where a Describe the W s for these data 5555 O A The two variables are the Scores 15 30 15 HTH b Name the variables and classify each as categorical or quantitative HOH Min 16 15 13 HIH Q and the OB Q1 17 18 15 c Create side by side boxplots to display these results as best you can with this information Create side by side boxplots where N represents the group with no caffeine L the group with low caffeine and H the group with high caffeine Choose the correct graph below 30 25 When How 10 5 Why which are G Median 21 22 18 and O C Scores 30 HIHO o N HOH variables respectively o H Q Q3 23 23 22 Q O D Scores HANNWW HH H NLH du Max 27 27 23

Cell phone user Not a cell phone user Total O 30 1000 O 490 500 O 10 500 Speeding violation 30 500 10 20 30 No speeding violation 490 480 970 Total Consider the table above Find the probability of selecting a person with speeding violation GIVEN that he she is a cell phone user 500 500 1000

Suppose that three different closely related diseases A1 A2 and A3 occur in 25 15 and 12 of the population Find the probability of disease A2 given B3 using the table below O 0 44 O 0 23 0 30 0 28 Symptom State B B B B3 B4 no symptoms Disease State A A 08 18 06 68 A2 17 12 07 64 A3 10 14 08 68

80 O 86 O 86 5 22 86 5 O 87 Question 6 Consider the following dataset 77 79 80 86 87 87 94 99 Compute the range

B There is no mode 5 50 SO 10 5 10 5 H Find the midrange The midrange is 9 6 inch es Type an integer or a decimal Do not round e Are the statistics representative of the current population of all women in that country s military Choose the best answer below OA Since the sample is random and the sample size is greater than 10 the sample can be considered to be representative of the population B Since the measurements were made in 1988 they are not necessarily representative of the current population of all women in the country s mili C Since the sample does not include men the sample should not be considered to be representative of the population D Since the sample is not a random sample it should not be considered to be representative of the population

Suppose that four random variables Y1 Y2 Y3 and Y4 follow a normal distribution with mean 5 and standard deviation 1 That is Y1 N 5 1 Y2 N 5 1 Y3 N 5 1 and Y4 N 5 1 What is the distribution of Y1 Y2 Y3 Y4 2 2 O N 5 4 ON 20 2 ON 20 6 ON 20 8

Suppose a quiz consist of 3 questions with 2 possible answer choices What is the probability that you get exactly 1 question correct 0 5 O 0 375 O 0 125 O 0 05

Of all sports football accounts for the highest incidence of concussion in the United States due to the large number of athletes participating and the nature of the sport While there is general agreement that concussion incidence can be reduced by making rule changes and teaching proper tackling technique there remains debate as to whether helmet design may also reduce the incidence of concussion Rowson et al 2014 report on a retrospective analysis of head impact data collected between 2005 and 2010 from eight collegiate football teams Concussion rates for players wearing two types of helmets Riddell VSR4 and Riddell Revolution were compared A total of 1 281 444 head impacts were recorded from which 64 concussions were diagnosed The relative risk of sustaining a concussion in a Revolution helmet compared with a VSR4 helmet was 46 1 This study illustrates that differences in the ability to reduce concussion risk exist between helmet models in football Although helmet design may never prevent all concussions from occurring in football evidence illustrates that it can reduce the incidence of this injury Identify the population that is of interest to the researchers O The 1 281 444 head impacts recorded O All head impacts resulting from playing football over a given period of time O The number or percent of concussions suffered through these impacts O The advances in tackling techniques imply that there is variability in how a tackle is performed

O mode PowerOutputs O mean 4000 3800 3600 3400 3200 In the box plot above what is the number at the red arrow O median O trimmed mean

Monthly sales figures for a particular food industry tend to be normally distributed with a mean of 155 thousand dollars and a standard deviation of 45 thousand dollars Compute the following P Y 155 01 0 5 O 0 25 O 0 1

The company that sells frozen pizza to stores in four markets in the United States Denver Baltimore Dallas and Chicago wants to examine the prices that the stores charge for pizza slices The accompanying boxplots compare data from a sample of stores in each market Complete parts a and b below a Do prices appear to be the same in the four markets Explain OA No prices appear to be both lower on average and more variable in Denver than in the other three cities B No prices appear to be lower on average in Chicago than in the other three cities C No prices appear to be both higher on average and more variable in Baltimore than in the other three cities OD Yes prices appear to be the same in the four markets b Does the presence of any outliers affect your overall conclusions about prices in the four markets OA No the presence of outliers does not affect the overall conclusions OB Yes Dallas s outlier increases its range compared to the ranges of the other cities OC Yes Baltimore s outliers increases its range compared to the ranges of the cities without outliers D Yes Chicago s outliers bring its average price down below the average prices of the other cities Price 15 3 0 25 20 1 5 F HIH HI tooo Denver Baltimore Dallas Market HIH Chicago

In an attempt to decrease drunk driving police set up vehicle checkpoints during the July 4 evening The police randomly select vehicles to be stopped for informational checks On a particular roadway assume that 20 of all drivers have a blood alcohol level above the legal limit For a random sample of 15 vehicles compute the probability that exactly 6 of the 15 drivers will excee the legal limit O 0 O 0 6 O 0 04 0 06

A patient visits her doctor with concerns about her blood pressure If the systolic blood pressure exceeds 150 the patient is considered to have high blood pressure and medication may be prescribed The problem is that there is a considerable variation in a patient s systolic blood pressure readings during a given day A patient s systolic readings during a given day have a normal distribution with a mean of 160 mm mercury and a standard deviation of 20 mm If five measurements are taken at various times during the day what is the probability that the average blood pressure reading will be less than 150 and hence fail to indicate that the patient has a high blood pressure problem 0 3085 O 0 1911 O 0 1314 O 0 5000

Let Z be a random variable with a standard normal distribution Find the value of Z denoted zo such that P Z Zo 0 975 O 0 50 O 0 975 O 1 96 O2 51

Find the area under the standard normal curve between these values z 0 and z 3 49 00 O 0 10 O 0 25 O 0 50

The z score tells you O how many standard deviations the value y is above to the right of or below to the left of the mean O how many units the value y is above to the right of or below to the left of the mean O how many standard measure the value y is above to the right of or below to the left of the mean O how many standard variance the value y is above to the right of or below to the left of the mean H

The accompanying dotplot shows the heights of some of the singers in a chorus collected so that the singers could be positioned on stage with shorter ones in front and taller ones in back Complete parts a and b Click the icon to view the dotplot CHILD a Describe the distribution Choose the correct answer below OA The distribution is unimodal There is a center at around 62 inches Its mode is near 60 inches The heights range from 60 to 76 inches with most heights between 68 and 70 inches OB The distribution is bimodal There is a center at around 65 66 inches and a smaller center around 70 inches Its modes are near 65 inches and 70 inches The heights range from 60 to 76 inches with most heights between 65 and 70 inches OC The distribution has no noticeable modes The heights range from 60 to 76 inches with most heights between 63 and 73 inches OD The distribution is multimodal with centers at around 62 66 and 70 inches Its modes are near 60 inches 65 inches and 70 inches The heights range from 60 to 76 inches with most heights between 65 and 66 inches b What is the most likely explanation for the features seen in the distribution OA The shape of the distribution is probably due to the fact that some of the singers wore heels and some did not OB The shape of the distribution is probably due to a mix of men and women in the group OC Height data do not usually take this shape but it does in this case because of how the singers are organized on stage OD Height data always take this shape because some people are tall and some are short Dotplot of height data 60 65 70 Height inches Q

A small warehouse employs a supervisor at 1400 a week an inventory manager at 750 a week six stock boys at 450 a week and four drivers at 490 a week a Find the mean and median wage The mean wage is The median wage is b How many employees earn more than the mean wage KILD 2 point s possible c Which measure of center best describes a typical wage at this company the mean or the median O A The median best describes the typical wage The mean is not a good measure of center because it is affected by the two higher salaries OB The median best describes the typical wage The mean is not a good measure of center because it is affected by the multitude of duplicate salaries OC The mean best describes the typical wage The median is not a good measure of center because it is affected by the two higher salaries OD The mean best describes the typical wage The median is not a good measure of center because it is affected by the multitude of duplicate salaries d Which measure of spread would best describe the payroll the range the IQR or the standard deviation Why OA The IQR is the better measure of spread The standard deviation and the range are both affected by the two higher salaries OB The standard deviation is the better measure of spread The IQR and the range are both affected by the two higher salaries OC The range is the better measure of spread Neither the IQR nor the standard deviation account for the extreme values OD The standard deviation is the better measure of spread Neither the IQR nor the range account for every data value

The accompanying display shows the average drive distance in yards for 199 professional golfers during a week on a tour in a recent year Complete parts a through d below Click the icon to view the display a Describe this distribution The distribution is and b Approximately what proportion of professional golfers drive on average 280 yards or less OA 90 B 75 C 20 O D 50 E 1 c Estimate the mean by examining the histogram Choose the correct answer below O A 270 yards B 300 yards C 280 yards D 310 yards OE 290 yards d Should the mean be expected to be smaller than approximately equal to or larger than the median Why Display of Goters 30 25 20 15 10 54 260 270 280 200 300 Average Drive Length yd Print Done 310 320 odu Q G 1

Here are boxplots of the points scored during the first 10 games of the season for both Scyrine and Alexandra a Summarize the similarities and differences in their performance so far b The coach can take only one player to the state championship Which one should she take Why a Choose the correct answer below O A Both girls have the same approximate mean but Alexandra has a larger IQR B Both girls have the same approximate median but Scyrine has a larger IQR OC Both players are about the same except Scyrine can score more points O D Both girls have the same approximate median and IQR but Scyrine has a larger range b Choose the correct answer below O A She should take Alexandra because she is a more consistent performer OB She should take Scyrine because she has the ability to score a higher point total OC It does not matter which player she takes because they both score the same average number of points A and B are both possible depending on the coach s preference Points 30 25 20 15 10 5 HIH 3 Scyrine Alexandra Player

Identify the Ws name the variables specify for each variable whether its use indicates that it should be treated as categorical or quantitative and for any quantitative variable identify the units in which it was measured In performing research for an ecology class students at a college in upstate New York collect data on streams each year They record a number of biological chemical and physical variables including the stream name the substrate of the stream limestone shale or mixed the acidity of the water pH the temperature C and the BCI a numerical measure of biological diversity Identify the Who in this situation Choose the correct answer below A The streams OB The biological organisms that contribute to the BCI OC The students D The college OE The Who is not specified Identify the What in this situation Select all that apply A Substrate of the stream B Name of stream C Acidity of the water D BCI E Temperature ME The W

The accompanying dotplot shows the carbohydrate content of 77 breakfast cereals in grams Complete parts a and b Click the icon to view the dotplot a Describe the distribution The distribution of cereal carbohydrates is with grams The data range from gram s to gram s with most c grams Type integers or decimals Do not round Use ascending order b Given what you know about breakfast cereals what additional variable do you think would help describe the shape you see on this graph OA Cereals have very specific government mandates requirements before they can be sold which probably explains the small spread B Very few cereal manufacturers take consumer health into account which probably explains the low number of dots below 10 grams C Cereals made for kids can be high in sugar and carbohydrates which probably explains the high number of dots at 21 grams D A lot of cereals are exactly the same which probably explains the number of tall columns of dots

Identify the W s name the variables specify for each variable whether its use indicates that it should be treated as categorical or quantitative and for any quantitative variable identify the units in which it was measured In performing research for an ecology class students at a college in upstate New York collect data on streams each year They record a number of biological chemical and physical variables including the stream name the substrate of the stream limestone shale or mixed the acidity of the water pH the temperature C and the BCI a numerical measure of biological diversity Identify the Why in this situation Choose the correct answer below O A To mine for precious stones OB To reduce the acidity of New York s streams OC To increase biological diversity OD The Why is not specified Identify the How in this situation Select all that apply OA Mixing several different stream waters together and watching for a reaction OB Swimming in the streams OC Gathering sample water from each stream and studying it back at the campus CCID

Shown to the right are the histogram and summary statistics for the number of camp sites at public parks in a particular state Use this information to complete parts a through d below a Which statistics would you use to identify the center and spread of this distribution Why Because the distribution is skewed the median b How many parks would you classify as outliers Explain 300 250 m A There are two outliers because two data values are more than 3 standard deviations from the mean B There are three outliers because three data values are more than 3 standard deviations from the mean C There are three outliers because three data values are either more than 1 5 IQRs below Q1 or more than 1 5 IQRS above Q3 D There are two outliers because two data values are either more than 1 5 IQRs below Q1 or more than 1 5 IQRS above Q3 E There are no parks that would be classified as outliers c Create a boxplot for these data Choose the correct boxplot below OA O B Q 300 250 m T Q should be used to describe the center and the quartiles and IQR should be used to describe the spread C 300 250 of Parks PAPP mm HO U 150 200 of Sites Park Q 100 O D 300 4 250 250 300 son HO a o Count 42 Mean 60 Median 44 StdDev 53 2 Min 0 Max 265 Q1 28 Q3 73

A medical researcher measures the increase in heart rate of patients who are taking a stress test What kind of variable is the researcher studying Choose the correct answer below O Quantitative variable Identifier variable Ordinal variable Categes Wahl

Given are histograms and the five number summaries for the average windspeeds in a particular region for the year 2011 and the year 2016 Compare these distributions and be sure to address shape including outliers if there are any center and spread Click the icon to view the histograms and five number summaries The distribution for 2011 is unimodal and skewed to the right while the distribution for 2016 is unimodal and skewed right buffess so than for 2011 There are for both distributions The center of the distribution for 2011 as measured by the is of the distribution for 2011 as measured by the is the spread of the distribution for 2016 Histograms and Five number Summaries of Days 100 80 60 40 20 2011 Average Wind Speed Year 2016 T Min 0 58 Q Q Q1 1 42 skeape 100 80 60 40 20 0 Median Q3 2 075 2 91 2016 2 3 4 Average Wind Speed Max 6 17 67 Q Q Ythe center of the distribution for 2016 The spri X D Time Remaining 00 29 42

The average score on the Stats midterm was 80 points with a standard deviation of 6 points and Karl s z score was 1 How many points did he score He scored points

The Centers for Disease Control lists causes of death in the United States during 2013 Each person is assigned only one cause of death Heart Cancer BOXER a Is it reasonable to conclude that heart or respiratory diseases were the cause of approximately 29 of U S deaths in 2013 A No because there is no possibility for overlap B Yes because there is no possibility for overlap C No because there is the possibility of overlap D Yes because there is the possibility of overlap b What percent of deaths were from causes not listed here Round to one decimal place as needed c Select the diagram that represents these data Circulatory or Stroke Respiratory Accidents Other Cause of Death Heart disease Cancer Circulatory diseases and stroke Respiratory diseases Accidents Heart Cancer Circulatory Respiratory diseases Accidents Percent 23 5 22 5 5 0 5 7 5 0

The cost C x where is the number of miles driven of renting a car for a day is 28 plus 1 45 per mile What is the slope of the linear function and its units select the correct units What is the y intercept and its units units What is the linear function C x C x Question Help Message instructor Select an answer Select an answer C Select an answer dollars miles per dollar miles

The brain volumes cm of 20 brains have a mean of 1084 2 cm and a standard deviation of 122 9 cm Use the given standard deviation and the range rule of thumb to identify the limits separating values that are significantly low or significantly high For such data would a brain volume of 1360 0 cm be significantly high Significantly low values are cm or lower Type an integer or a decimal Do not round 0

isted below are amounts in millions of dollars collected from parking meters by a security service company and other companies during similar time periods Do the mited data listed here show evidence of stealing by the security service company s employees 1 5 1 6 Security Service Company Other Companies Find the coefficient of variation for each of the two samples then compare the variation 1 8 1 8 1 6 1 5 1 7 1 9 The coefficient of variation for the amount collected by the security service company is Round to one decimal place as needed 1 5 1 6 1 3 1 8 1 8 1 6 1 4 1 7 1 4 1 9 1 7 C 1 6

ind the a mean b isted below are foot lengths in inches of randomly selected women in a study of a country s military in 1988 Are the statistics representative of the current population f all women in that country s military 9 7 8 7 10 5 8 7 9 4 9 1 Find the mean 10 4 8 8 9 6 10 5 10 5

33 Observation versus experiment Researchers at the University of Pennsylvania found that patients who are divorced separated or widowed had approximately a 40 greater chance of dying or developing a new func tional disability in the first two years following cardiac surgery than their married peers The data included 1576 subjects who underwent cardiac surgery of which 65 were married 33 were divorced separated or widowed and 2 had never been married The find ings were reported to be statistically significant 25 a Without reading any further details of this study how do you know that this was an observational study b Suggest some variables that might differ between the subjects in the study who were married versus those who are divorced separated or widowed Are any of these possible confounding variables Explain c Summarize briefly the limitations of this study Despite these limitations explain why this study still furniches useful information in formulating a

3 1 Terminology 66 1200 1000 800 600 400 200 D 1045 40 60 Total Figure 3 20 82 70 18 34 138 41 59 226 45 55 268 49 51 55 64 331 48 52 65 478 35 44 45 54 Sample Percent approve Percent disapprove 44 56 Male 567 37 63 Female 100 096 The graph in Figure 3 20 displays the sample sizes and percentages of people in different age and gender groups who were polled concerning their approval of Mayor Ford s actions in office The total number in the sample of all the age groups is 1 045 a Define three events in the graph 6 Describe in words what the entry 40 means c Describe in words the complement of the entry in the previous question A d Describe in words what the entry 30 means e Out of the males and females what percent are males f Out of the females what percent disapprove of Mayor Ford g Out of all the age groups what percent approve of Mayor Ford h Find P Approve Male i Out of the age groups what percent are more than 44 years old J Find P Approve Age 35

5 Getting teachers to come to school Elementary schools in rural India are usually small with a single teacher The teachers often fail to show up for work Here is an idea for improving attendance give the teacher a digital camera with a tamper proof time and date stamp and ask a student to take a photo of the teacher and class at the beginning and end of the day Offer the teacher better pay for good attendance verified by the photos Will this work A randomized comparative experiment started with 120 rural schools in Rajasthan and as signed 60 to this treatment and 60 to a control group Random checks for teacher attendance showed that 21 of teachers in the treatment group were absent as opposed to 42 in the control group 27 a Outline the design of this experiment b Label the schools and choose the first 10 schools for the treatment group If you use Table B start at

43 Liquid water enhancers Bottled water flavored and plain is expected to become the largest segment of the liquid refreshment market by the end of this decade surpassing traditional carbonated soft drinks 34 Kraft s MiO a liquid water enhancer comes in a variety of fla vors and a few drops added to water gives a zero calorie flavored water drink You wonder if those who drink flavored water like the taste of MiO as well as they like the taste of a competing flavored water product that comes ready to drink a Describe a matched pairs experiment to answer this question Be sure to include proper blinding of your subjects What is your response variable going to be b You have 20 people on hand who prefer to drink flavored water Use the Simple Random Sample applet software or Table B at line 138 to do the

3 2 Independent and Mutually Exclusive Events Use the following information to answer the next 12 exercises The graph shown is based on more than 170 000 interviews that took place from January through December 2012 The sample consists of employed Americans 18 years of age or older The Health Index Scores are the sample space We randomly sample one type of Health Index Score the emotional well being score Occupation Service Transportation Manufacturing or production Sales Clerical or office Installation and repair Construction or mining Manager executive or official Business owner Nurse Professional Farming fishing or forestry Teacher K 12 Physician Figure 3 21 77 78 79 80 Health Index Score 81 82 83 84 85 68 Find the probability that a Health Index Score is 82 7 69 Find the probability that a Health Index Score is 81 0 70 Find the probability that a Health Index Score is more than 81 71 Find the probability that a Health Index Score is between 80 5 and 82 72 If we know a Health Index Score is 81 5 or more what is the probability that it is 82 7 73 What is the probability that a Health Index Score is 80 7 or 82 7 74 What is the probability that a Health Index Score is less than 80 2 given that it is already less than 81 75 What occupation has the highest Health Index Score 76 What occupation has the lowest emotional index score 77 What is the range of the data

47 Wine beer or spirits There is good evidence that mod erate alcohol use improves health Some people think that red wine is better for your health than other alco holic drinks You have recruited 300 adults aged 45 65 who are willing to follow your orders about alcohol con sumption over the next five years You want to compare the effects on heart disease of moderate drinking of just red wine just beer or just spirits Outline the design of a completely randomized experiment to do this No such experiment has been done because subjects aren t

3 Quitting Smoking and Risk for Type 2 Diabetes Researchers studied a group of 10 892 middle aged adults over a period of nine years They found that smokers who quit had a higher risk of diabetes within three years of quitting than either nonsmokers or continuing smokers Does this show that stopping smoking causes the short term risk for Type 2 diabetes to increase Weight gain has been shown to be a major risk factor for developing Type 2 diabetes and is often a side effect of quitting smoking Smokers also often quit due to health reasons Based on this research should you tell a middle aged adult who smokes that stopping smoking can cause diabetes and advise him or her to continue smoking Carefully explain your answers to both questions

15 Does Meditation Reduce Anxiety An experiment that claimed to show that meditation reduces anxiety proceeded as follows The experimenter in terviewed the subjects and rated their level of anxiety Then the subjects were randomly assigned to two groups The experimenter taught one group how to meditate and they meditated daily for a month The other group was simply told to relax more At the end of the month the experimenter interviewed all the subjects again and rated their anxiety level The meditation group now had less anxiety Psychologists said that the results were suspect because the ratings were not blind Explain what this means and how lack of blindness could bias the reported results mized laola

31 Don t stop exercising An investigation of the effect of different levels of physical activity was conducted on identical male twins in Finland For each twin pair al though they had maintained the same activity level for most of their lives one twin had significantly reduced his or her activity over the last few years due to work or family pressures For each pair of twins body fat per centage endurance levels and insulin sensitivity were measured For the less active twin the results showed greater body fat worse endurance and levels of insulin sensitivity displaying early signs of metabolic disease 23 a What type of design is being used in this investiga tion Give the explanatory and response variables b Is this an experiment or an observational study Why c The article reports that the measurements were car

Kraft Foods successfully introduced DiGiorno Pizza into the marketplace in 1996 Kraft conducted extensive research about the product and the marketplace before introducing this product to the public Many questions had to be answered before Kraft began production For example why do people eat pizza When do they eat pizza SMI Alcott conducted a research study for Kraft in which they sent out 1000 surveys to pizza lovers The results indicated that people ate pizza during fun social occasions or at home when no one wanted to cook People used frozen pizza mostly for convenience but selected carry out pizza for a variety of other reasons including quality and avoidance of cooking The Loran Marketing Group conducted focus groups for Kraft with women aged 25 to 54 Their findings showed that consumers used frozen pizza for convenience but wanted carry out pizza taste Kraft researchers realized that if they were to launch a successful frozen pizza that could compete with carry out pizza they had to develop a frozen pizza that a had restaurant takeout quality b had the convenience of freezer storage To satisfy these seemingly divergent goals Kraft developed DiGiorno Pizza This impressed focus group members and in a series of blind taste tests conducted by Product Dynamics DiGiorno Pizza beat out all frozen pizzas and finished second overall behind one carry out brand DiGiorno Pizza has continued to grow in sales and market share over the years According to AIB International DiGiorno Pizza was by far the top frozen pizza brand in the U S in 2011 which sales of 677 million when compared to the next brand which had sales of 294 million Instructions Can you think of any descriptive statistics that might have been used by Kraft in their decision making process

13 Healthy Diet and Cataracts The relationship between healthy diet and prevalence of cataracts was assessed using a sample of 1808 participants from the Women s Health Initiative Observational Study Having a high Healthy Eat ing Index score was the strongest predictor of a reduced risk of cataracts among modifiable behaviors considered The Healthy Eating Index score was created by the U S Department of Agriculture and measures how well a person s diet con forms to recommended healthy eating patterns The report concludes These data add to the body of evidence suggesting that eating foods rich in a variety of vitamins and minerals may contribute to postponing the occurrence of the most common type of cataract in the United States 12 a Explain why this is an observational study rather than an experiment b Although the result was statistically significant the authors did not use strong language in stating their conclusions instead using words such as suggesting and may Do you think that their language is appropriate given the nature of the study Why

7 Reducing Unemployment Will cash bonuses speed the return to work of unemployed people A state department of labor notes that last year 41 of people who filed claims for unemployment insurance found a new job within 15 weeks As an experiment the state offers 500 to people filing unemploy ment claims if they find a job within 15 weeks The percent who do so increases to 53 Suggest some conditions that might make it easier or harder to find a job this year as opposed to last year Confounding with these lurking variables makes it impossible to say whether the 500 bonus really caused the increase

d t 1 5t The function models d the distance in meters a car travels after t seco of constant acceleration from rest What is the distance in meters the c travels in 6 seconds

Points 0 33 of 1 Fast food is often considered unhealthy because much of it is high in both fat and sodium But are the two related Here are the fat and sodium contents of several brands of burgers Analyze the association between fat content and sodium using correlation and scatterplots Fat g Sodium mg OA Sodium mg 1700 700 10 Fat g 19 29 35 924 1496 1317 Q 2 39 41 41 45 850 1172 930 1267 OB Sodium mg 1700 Part 3 of 3 700 1 10 Fat a D What is the correlation coefficient for the data 0 029 Round to three decimal places as needed Which of the following best describes the association between fat content and sodium OA There is a moderate positive linear association OB There is a strong positive linear association OC There is a moderate negative linear association OD There is a strong curved association OE There is a strong negative linear association OF There is no apparent association between fat content and sodium Sodium mg 1700 7001 10 Fat g Q Q OD Sodum mg 1700 700 10 Fat g Q

2000 2500 3000 3500 4000 4500 5000 300 5500 6000

K ev The diameters of ball bearings are distributed normally The mean diameter is 134 millimeters and the standard deviation is 3 millimeters Find the probability that the diameter of a selected bearing is greater than 131 millimeters Round your answer to four decimal places Answer 2 Points Keypad Keyboard Shortcuts If you would like to look up the value in a table select the table you want to view then either click the cell at the intersection of the row and column or use the arrow keys to find the appropriate cell in the table and select it using the Space key Normal Table 00 to z Normal Table to z Ne

Find the area under the standard normal curve to the left of z 2 11 Round your answer to four decimal places if necessary Answer 2 Points K Keyboard S If you would like to look up the value in a table select the table you want to view then either click the cell at the intersection of the row and colu use the arrow keys to find the appropriate cell in the table and select it using the Space key Normal Table to z

Consider the accompanying data and scatterplot of the data from a small bookstore Find the correlation coefficient for the given data An earlier analysis found that the data had a moderately strong positive linear association Describe how this value confirms this relationship Think carefully about all the things you know from thi alue Click the icon to view the bookstore data and scatterplot pr 0 Round to three decimal pl Sales People and Sales Number of Sales People Working 4 6 9 10 10 13 15 17 21 x 10 6 SD x 6 10 Sales in 1000 9 10 14 14 22222 18 21 20 23 26 x 17 7 SD x 5 72 Q Q 3 D X