Statistics Questions and Answers

For each question below please select the sampling method that most closely matches the description You may use each method more than once a In a city a list was obtained from each of the 5 neighborhoods in town and five people were randomly chosen from each neighborhood to be interviewed by the city mayor Select an answer Details b You want to investigate the voter s opinions on an upcoming issue for your city The city that you live in has 12 different neighborhoods You randomly select 10 registered voters from each neighborhood and contact them to ask for their opinion Select an answer c You work for a company as a quality control specialist You want to check the current production of products for defects Your factory has 5 different assembly lines At the end of the day you randomly choose two of the assembly lines and inspect each item produced by that assembly line Select an answer d You work for a company as a quality control specialist You want to check the current production of products for defects You locate the finished products for the day and inspect the first 20 items you happen to see Select an answer e You work for a company as a quality control specialist You want to check the current production of products for defects At the end of the day you assign a number to each item that was produced You randomly choose 20 numbers and inspect the items that correspond to the randomly chosen numbers Select an answer

The heights of 10 year olds regardless of gender closely follow a Normal distribution with a mean of 54 inches and a standard deviation of 7 inches a What is the probability that a randomly chosen 10 year old is shorter than 47 inches Round to 4 decimal places b If the tallest 10 of the class is considered very tall what is the height cutoff for very tall Round to 2 decimal places

You would like to investigate whether smokers are more likely than nonsmokers to get lung cancer You take the students in your class select half at random and tell them to smoke a pack of cigarettes each day and you tell the other half not to ever smoke Fifty years from now you will analyze whether more smokers than nonsmokers got lung cancer a Is this an experiment or an observational study O Experiment O Observational Study b Summarize at least three issues or practical difficulties with this plan

1 3 points The scatterplot below represents students grades based on the time they spent watching TV Students grades on exam based on time spent watching TV Grade 9 100 1 2 3 4 5 6 7 8 9 Time spent watching TV hours a Is the relationship between a student s grade and the time spent watching TV linear on non linear If linear is it direct or partial positive or negative strong or weak b What would be the best estimate of time spent watching TV for a student who earned a grade of 70

No 12345678 S52255289 9 10 11 12 345 14 16 17 18 19 20 21 222222788 23 24 25 26 credits 29 15 15 20 12 15 15 7 20 20 10 15 15 15 18 15 15 20 20 15 20 2521225555 20 17 10 20 GPA 4 3 99 4 2 9 3 99 3 8 0 3 52 3 85 3 97 4 3 3 3 8 3 98 2 7 3 9 3 89 3 99 3 97 3 93 3 9 3 94 3 56 3 66 3 4 3 85 3 65 3 82 3 97 GPA exp study hrs study hrs sleep hrs meals coolmeals take exer hrs music 10 18 5 No 5 Yes 2 Yes 5 Yes 3 Yes 4 4 4 4 4 3 8 3 3 5 3 8 4 4 3 8 4 4 2 6 4 3 9 4 44 4 448484488 3 8 3 8 3 8 3 8 30 35 24 30 21 45 20 48 25 4 18 12 18 35 24 24 20 20 10 12 35 15 25 33 28 30 20 40 40 15 6 15 7 22 10 20 12 4 7562087 288028 12 10 5 7 8 15 6 8 10 12 8688 0 0 0 0 0 0 6 7 9 6 6 7 5 8 8 7 7 8 7 7 8 8 8 8 8 8 7 14 10 3 10 1 14 14 654554 OW NG NOWA SI 5 5 2 15 3 9 6 15 14 14 3 2 7 2 4 4 5 1 0 1 4 4 3 4 3 3 sewhosoa WANW Ow 10 3 3 6 0 0 5 0 14 3 3 15 20 No 1 No 2 No 2 No 4 No 1 No 2 No 3 Yes 3 No 2 No 6 Yes 4 Yes 5 Yes 3 No 0 Yes 8 No 3 Yes 1 No 4 Yes 7 No 0 No 5 Yes 5 No 3 Yes instruments meditate No No Yes less often than once per week Guitar Guitar Piano Violi No Piano No Yes several times per week No No Yes less often than once per week No No Piano Violi Yes less often than once per week No Piano Piano Drums Yes several times per week No Piano Uku No Piano No Yes daily Yes less often than once per week No Drums Piano Yes daily Yes about once per week No Yes daily Yes daily Yes less often than once per week No No Harmonica No ck a categorical variable from the Math 211 Student Survey data set and treat the Math 1 students who responded to this survey as a random sample of Shoreline Community ollege students Pose a question that could be answered using the tools from Chapter and run through a full analysis of the inferences you can draw including a hypothesis est confidence interval and a discussion of whether the relevant conditions are truly tisfied

2 4 points The following scatterplot represents the number of mosquitoes in a swamp over a period of time Mosquitoes per square foot 100 90 80 70 50 40 30 2220 10 0 Mosquitoes per square foot in swamp 1900 1920 Year a Describe the trend in the number of mosquitoes in the swamp over time b What is a good estimate for the number of mosquitoes in the swamp in 1914 How many mosquitoes would you expect to find per square foot in 1938

According to a recent Gallup Poll 13 of Americans believe that healthcare is the most important problem in America Let be the proportion of people who believe that healthcare is the most important problem in America out of a random sample of 223 Americans Determine the following probabilities Round probability solutions to four decimal places and values to two decimal places if necessary Find the probability that in a random sample of 223 Americans at most 22 people believe that healthcare is the most important problem in America P p Find the probability that in a random sample of 223 Americans between 20 and 36 people believe that healthcare is the most important problem in America Hint First calculate the sample proportions p for each probability exercise The value of is calculated by taking the number

Consider a population of size N 9 700 with a mean of 170 and standard deviation of o 24 Compute the following z values for either the population distribution or the sampling distributions of with given sample size Round solutions to two decimal places if necessary Suppose a random single observations is selected from the population Calculate the z value that corresponds to x 172 Suppose a random single observations is selected from the population Calculate the z value that corresponds to x 178 Suppose a random sample of 83 observations is selected from the population Calculate the z value that corresponds to 167 Suppose a random sample of 60 observations is selected from the population Calculate the z value that corresponds to 165

know the definition of Economic Growth Be able to list the factors of economic growth Be able to define the business cycle know the four stages in order Know the definitions of unemployment and the labor force and how to calculate the unemployment rate Know about the three types of unemployment and the NRU know the economic costs of unemployment Know the definition of inflation and how to measure it Know the two types of inflation and their causes

The accompanying frequency distribution summarizes sample data consisting of ages of randomly selected inmates in federal prisons Use the data to construct a 95 confidence interval estimate of the mean age of all inmates in federal prisons Age years 16 25 26 35 36 45 46 55 56 65 Over 65 Using the class limits of 66 75 for the over 65 group find the confidence interval Round to one decimal place as needed Number 14 62 66 37 14 6 19

Assume that the sample is a simple random sample obtained from a normally distributed population of weights of the aspirin in Bayer tablets Use the table below to find the minimum sample size needed to be 95 confident that the sample standard deviation s is within 30 of o Is this sample size practical 0 To be 95 confident that s is within of the value of o the sample size n should be at least To be 99 confident that s is within of the value of o the sample size n should be at least 1 5 10 20 30 40 50 19 205 768 1 5 10 20 30 40 50 S 192 48 21 12 33 218 1 336 336 85 38 22 8 14

Some states have college admission programs that guarantee the top p of high school graduates in terms of GPA admission into a state university Suppose a state guarantees the top 14 of high school students admission into its university system In addition suppose the distribution of all high school students GPAs are normally distributed with a mean of 2 89 and standard deviation of 0 26 Determine the minimum GPA required for a student to be guaranteed admission into the state s university system Round the solution to two decimal places if necessary GPA

According to Experian the average credit score of and American adult is 728 and the standard deviation of all credit scores of American adults is 63 Determine the following probabilities Round solutions to four decimal places if necessary Determine the probability that a randomly selected American adult has a credit score greater than or equal to 734 P x 734 Determine the probability that a randomly selected American adult has a credit score between 735 and 841 P 735 x 841

According to the Okeechobee Economic Development Council the average household income in Okeechobee county is 47 525 with a standard deviation of 1 220 Determine the following probabilities Round solutions to four decimal places if necessary Determine the probability that a randomly selected Okeechobee county household has an income less than or equal to 49 337 P x 49 337 Determine the probability that a randomly selected Okeechobee county household has an income between 44 488 and 46 680 P 44 488 x 46 680

The graph of the standard normal distribution is given below The standa normal distribution has a mean of 0 and a standard deviation of 1 It is often abbreviated by N 0 1 5 4 3 2 N 0 0 85 N 2 1 05 04 9 1 03 0 2 0 1 0 1 0 5 The four graphs below are not standard normal distributions Determine which graph matches each distribution description 04 Hint Recall that the mean affects the position of the distribution whereas the standard deviation affects the shape height of the graph 0 3 0 2 0 1 5 4 3 2 J 0 1 0 5 04 93 1 0 2 01 2 1 3 2 3 4 5 4 Q

Suppose that 60 of voters in St Lucie county support a ballot measure to raise property taxes Consider the sampling distribution of the sample proportion of supporters with sample size n 302 Determine the mean and standard deviation of the sampling distribution of p Round solutions to four decimal places if necessary What is the mean of this distribution 15 What is the standard error of this distribution

78 of owned dogs in the United States are spayed or neutered Round your answers to four decimal places If 46 owned dogs are randomly selected find the probability that a Exactly 38 of them are spayed or neutered b At most 38 of them are spayed or neutered c At least 33 of them are spayed or neutered d Between 34 and 42 including 34 and 42 of them are spayed or neutered

For each statistic parameter pair below calculate the sampling error Suppose a population has a mean of 143 and a random sample of size n 148 drawn from this population has a sample mean of 144 Determine the sampling error of Suppose a population has a standard deviation of o 71 and a random sample of size n 138 drawn from this population has a sample standard deviation of s 68 Determine the sampling error of s Suppose 73 of a population possesses a given characteristic and 55 of a random sample of size n 176 drawn from this population possesses the same characteristic Determine the sampling error of p

The distribution of the runtimes of all movies is known to be skewed to the left with a mean of 97 minutes and a standard deviation of 3 5 minutes Use this information to determine the following probabilities Round solutions to four decimal places if necessary Find the probability that a random sample of 72 movies has a mean runtime greater than 97 5 minutes P 97 5 Find the probability that a random sample of 72 movies has a mean runtime between 95 7 and 96 7 minutes P 95 796 7

Suppose a right skewed distribution exists with a mean of 144 and standard deviation of 11 Consider a random sample of 92 observations Use this information to determine the following probabilities Round solutions to four decimal places if necessary Find the probability that a random sample of size 92 has a mean greater than 144 P 144 Find the probability that a random sample of size 92 has a mean between 140 and 147 P 140 147

The average cost to rent a single family home in Stuart is 1 866 per month Assume that the distribution of the monthly rent of all single family homes in Stuart is normally distributed with a standard deviation of 117 Use this information to determine the following probabilities Round solutions to four decimal places if necessary Find the probability that a random sample of 139 homes in Stuart has a mean rent less than 1 849 P 1849 Find the probability that a random sample of 139 homes in Stuart has a mean rent between 1 840 and 1 885 P 1840 1885

Find the area under the standard normal curve between z 1 31 and z 0 04 Round the solution to four decimal places if necessary Area

In a test of weight loss programs 40 adults used the Atkins weight loss program After 12 months their mean weight loss was found to be 2 1 lb with a standard deviation of 4 8 lb Construct a 90 confidence interval estimate of the standard deviation of the weight loss for all such subjects Does the confidence interval give us information about the effectiveness of the diet In the above problem please write out the work for each of the following steps Please note that you do not have to number these steps but your work should correspond with them 1 Read the problem carefully to determine which type of analysis is being performed 2 Identify the parameter being estimated 3 Write down the formula s used 4 Determine the information needed to calculate the confidence interval estimate from the problem 5 Substitute all the values found in step 4 into either o 6 Follow the rounding rules established in week 3 Write a summary sentence 7 Answer any follow up questions 7 1 8 X n 1 xi

14 5 Use least squares regression to fit a straight line 11 12 15 17 19 8 8 10 12 12 X y 05 26 47 99 4 6 7 6 9 9 Along with the slope and intercept compute the standard error of the estimate and the correlation coefficient Plot the data and the regression line Then repeat the problem but regress x versus y switch the variables Interpret your results

Chapter 07 Aplia Assignment You have been a long time member of the local credit union Last week when you stopped by to make a deposit the customer service representative was rude and condescending You chose not to mention it to the branch manager This afternoon you experienced the same rude treatment from the same representative You are a personal friend of the branch manager and know that she would be upset if she knew clients were being treated disrespectfully You decide to send a note providing some constructive criticism Consider your intent in this situation Should you send the constructive criticism O Yes The branch manager deserves the opportunity to improve customer service at her location O No The representative would get in trouble and might even be fired Read the constructive criticism message and then answer the corresponding question To the Mobile Minute Manager Your customer service representative named Jenny Livingstone is incredibly rude and obnoxious Yesterday evening when I called to confirm the number of minutes left on my monthly plan she told me to check the website When I told her that my Internet was down she told me to go to the library because I was tying up the line and her main job was to help people pay their bills I don t think she has a high school education and that reflects really poorly on your company and on her

Experiment A box contains tiles labeled A through Z A tile is randomly chosen from the box and set aside Then another random selection is made from the remaining tiles A paper clip is randomly selected from a container with black clips and white clips and thrown away Then another random selection is made from the remaining clips A spinner with slices numbered 1 through 12 is spun twice Ivanna randomly selects one of her sports trading cards She then returns the card to the deck and mixes the deck Then another random selection is made A bag contains red beans and orange beans A bean is selected from the bag and dropped back into the bag The beans are mixed Then another random selection is made Events Event A The first selection is a tile labeled with a B Event B The second selection is a tile labeled with a P Event A The first selection is a black paper clip Event B The second selection is a white paper clip Event A The first spin lands on 8 Event B The second spin lands on 4 Event A The first selection is a baseball player Event B The second selection is a tennis player Event A The first selection is a red bean Event B The second selection is an orange bean Independent Dependent

Experiment A deck contains 14 cards numbered 1 through 14 A card is randomly selected and reinserted into the deck The deck is shuffled Then another random selection is made Henry randomly selects a sock from a drawer containing black socks and brown socks and puts it on Then another random selection is made from the remaining socks A family has two children A number cube with sides labeled 1 through 6 is rolled twice A litter of puppies consists of black puppies and white puppies A puppy is randomly selected and removed from the litter Then another random selection is made from the remaining puppies Events Event A The first selection is a 7 Event B The second selection is a 4 Event A The first selection is black Event B The second selection is brown Event A The older child has red hair Event B Both children have red hair Event A The first roll is a 2 Event B The second roll is a 5 Event A The first selection is a white puppy Event B The second selection is a black Independent Dependent

puppy has been tracking its weight at the end of each month since it was born She was told by the dog s breeder that the dog should have an adult weight somewhere between 45 and 50 pounds End of Month Answer 1 2 3 4 5 6 7 8 9 10 11 12 Step 2 of 2 How do you interpret the result from the previous step Weight in pounds 2 7 11 17 20 24 26 32 37 41 43 46 The linear model doesn t seem realistic The linear model seems realistic Keypas Keyboard Shortc

x Topic 11 12 Prob Stats Exam savvasrealize com assignments viewer clas YouTube nMenus Fayette Co Google lize Topic 11 12 Prob Stats Exam Part 2 AA2 L Google Drive marks

In your monthly budget you have noticed that you spend Groceries 1150 per month Utilities 210 per month Rent 1400 per month Internet and Phone 175 Other 350 What angle would Rent occupy in a Pie Chart Round to the one and do not input any units

For a given sample of data points A 12 3 5 7 7 9 11 108 10 12 13 2 3 5 calculate the z score for x 5 Round to the hundredth

The number of different license plates that have K E M P in that order is 1 Part 2 3 Part 3 of 3 c If your name is Kemp what is the probability that your name is on your license plate Write your answer as a fraction or a decimal rounded to at le 8 places

Find the median age Find the interquartile range 20 24 22 12 Tar 122 Players Ages 30 40 6 Find the range 10 20 20 farge 20 8 Find the age of the oldest player

8 The table below shows the number of grams of carbohydrates x and the number of Calories y of six different foods LL Carbohydrates x 8 9 5 10 6 7 4 22 Calories y 120 138 147 88 108 62 9 y ax b L 14 112 51833 a State the linear regression equation Round all values to the nearest hundredth b State the correlation coefficient to the nearest hundredth New a se b ca

Experiment A bean is randomly selected from a bag containing red beans and white beans and eaten Then another random selection is made from the remaining beans A deck contains 8 cards numbered 1 through 8 A card is randomly chosen from the deck The card is then put back into the deck The deck is shuffled Then another random selection is made A number cube with sides labeled 1 through 6 is rolled Then a with slices numbered 1 through 11 is spun A bin contains marbles numbered 1 through 8 A marble is randomly selected from the bin and returned to the bin The marbles are mixed Then another random selection is made A family has two children Events Event A The first selection is a white bean Event B The second selection is a red bean Event A The first card selected is numbered 7 Event B The second card selected is numbered 5 Event A The number cube roll is an even number Event B The spinner lands on an odd number Event A The first selection is an odd numbered marble Event B The second selection is an even numbered marble Event A The older child is a boy Event B Both children are boys Independent Dependent O

Find the value of Z0 04 Round to two decimal places O A 0 52 B 1 88 O C 1 75 D 1 75

Assume a population of 46 50 52 and 57 Assume that samples of size n 2 are randomly selected with replacement from the population Listed below are the sixteen different samples Complete parts a through c 46 46 52 46 V 46 50 52 50 T 46 52 52 52 0 Sample Median Y 1 a Find the median of each of the sixteen samples then summarize the sampling distribution of the medians in the format of a table representing the probability distribution of the distinct median values Use ascending order of the sample medians Probability Sample Median Y T 46 57 52 57 Probability 7 7 50 46 57 46 Tyne inteners or simp fractions Use ascending order of the sample medians CITE 50 50 57 50 50 52 57 52 50 57 57 57 O

Find the value of Z0 2 Round to two decimal places OA 0 84 OB 0 84 OC 0 58 O D 0 8

An automobile manufacturing plant produced 33 vehicles today 15 were trucks 5 were sedans and 13 were vans Each vehicle falls into only one of these categories Plant managers are going to select two of these vehicles for a thorough inspection The first vehicle will be selected at random and then the second vehicle will be selected at random from the remaining vehicles What is the probability that the first vehicle selected is a truck and the second vehicle is a sedan Do not round your intermediate computations Round your final answer to three decimal places If necessary consult a list of formulas BU Aa V

A group of 118 doctors and nurses volunteered to run a health fair Each volunteer worked one shift The table below summarizes the data on the volunteers and their shifts Doctor Nurse Morning Afternoon Evening 6 33 24 24 15 16 Suppose a volunteer from the health fair is chosen at random Answer each part Do not round intermediate computations and round your answers to the nearest hundredth If necessary consult a list of formulas a What is the probability that the volunteer is a nurse or worked the morning shift 0 b What is the probability that the volunteer is a doctor given that the volunteer worked the afternoon shift X C

Events A and B are mutually exclusive Suppose event A occurs with probability 0 11 and event B occurs with probability 0 17 Compute the following If necessary consult a list of formulas a Compute the probability that B occurs but A does not occur 0 b Compute the probability that either A occurs without B occurring or A and B both occur 0 X 5

K OrganicPlus processes organic milk into plain yogurt OrganicPlus 830 yields 750 gallons of plain yogurt OrganicPlus sells the one OrganicPlus wonders if it would be more profitable to sell individua 16 000 individual portions 3 4 cup each of fruited yogurt A recent would cost 0 07 per portion and fruit would cost 0 12 per portion plain yogurt into individual sized portions of fruited yogurt process Calculate the net benefit per batch under each alternative Enter Sales revenue per unit

A university class has 23 students 4 are psychology majors 8 are accounting majors and 11 are art majors Each student has only one of these majors The professor is planning to select two of the students for a demonstration The first student will be selected at random and then the second student will be selected at random from the remaining students What is the probability that the first student selected is a psychology major and the second student is an accounting major Do not round your intermediate computations Round your final answer to three decimal places If necessary consult a list of formulas Aa

A way of resolving conflict outside of the court system ntangible costs such as pain and suffering One of the three types of non fault states s not allowed with Limits of Liability Referred to as no fault coverage

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a sim qu rmal distribution find bilty accurate to 4 decim

An extensive study in Antarctica concluded that the mean height of adult emperor penguins in the wild is 44 5 in Cassandra believes that captive emperor penguins have a greater mean height due to better nutrition To test this idea she decides to conduct a one sample t test to see if the mean height of captive emperor penguins is greater than 44 5 in She selects a simple random sample of 26 penguins from different zoos around the country and has each penguin measured The summary statistics of the sample are given below Sample size n 26 Sample mean x 45 6 in Sample standard deviation S 4 3 in The heights of emperor penguins are normally distributed and there are no outliers in the sample Construct the null and alternative hypothesis for the appropriate one sample t test for the mean height of captive emperor penguins Ho H

Suppose that SAT math scores for all college bound high school seniors are known to be normally distributed with a mean of 500 and a standard deviation of 100 The guidance counselor at a charter school with a focus on math and science wants to compare her students performance on the math section of the SAT to that of all college bound seniors To do this she selects a random sample of 34 college bound seniors from her school and finds that the mean SAT math score for these students is 525 3 The guidance counselor plans to use a one sample z test to determine whether or not students at her school achieve better scores on the math section of the SAT than the general population of college bound seniors Choose the appropriate null and alternative hypotheses for such a test Ho 500 and H X 500 O Ho 525 3 and H 525 3 500 and H 500 Ho Ho 525 3 and H X 525 3 O Ho H 500 and H 500

At a local college 51 of the male students are smokers and 459 are non smokers Of the female students 235 are smokers and 265 are non smokers A male student and a female student from the college are randomly selected for a survey What is the probability that both are non smokers Do not round your answer If necessary consult a list of formulas

A sample of 267 adults is selected The adults are classified according to voter registration status registered or not registered They are also classified according to preferred source of current events information television newspapers radio or internet sites The results are given in the contingency table below Registered Not registered Television 34 19 Newspapers Radio Internet sites 40 33 39 44 40 18 What is the relative frequency of adults in the sample who are not registered to vote Round your answer to two decimal places