Statistics Questions and Answers

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Democrats Republicans Let be the population proportion for favor HO TL Democrates republican H1 TL Democrates Tre republican Use a significance level of 01 and determine whether the opinions on the tax cut proposal and the party affiliation are independent The expected frequency table Democrats Republicans 85 118 Under null hypothesis the overall proportion of favor is P 85 118 78 61 Favor 96 7514 6 106 248 5 Oppose 66 2485 Favor 4 85 118 72 7514 6 Oppose 163 78 61 179 59 36

Suppose that the mean cranial capacity for men is 1180 cc cubic centimeters and that the standard deviation is 300 cc Assuming that men s cranial capacities are normally distributed complete the following statements a Approximately 1480 cc of men have cranial capacities between 880 cc and b Approximately 99 7 of men have cranial capacities between cc and cc

the normal distribution shown below The mean of the distribution is 77 3 points and the standard deviation is 4 8 points In the figure v is a number along the axis and is under the highest part of the curve And u and w are numbers along the axis that are each the same distance away from v Use the empirical rule to choose the best value for the percentage of the area under the curve that is shaded and find the values of u v and w 60 1 U 65 Percentage of total area shaded Choose one 70 75 V 80 85 90 W 95

Most regression results related to statistical significance are reported as Three tailed Zero tailed One tailed Two tailed

When we want to visually examine the relationship between two ratio level variables the most common type of graph to use is the bar graph histogram the pie graph the scatterplot

With simple regression if we want to know the size of the effect i e the size of the relationship between the IV and DV the best statistic to look at is the correlation coefficient r squared the slope the constant

If the slope is 4 X is 7 and the constant is 3 what is Y O 5 31 O 15

With simple regression if we want to know the strength of the relationship or how good a predictor the IV is for the DV the best statistic to look at is the constant the slope R squared p value 10 1 point A researcher looks at two variables the number of cats people own and the number of dogs people own She finds that the correlation coefficient is 84 The best interpretation of this value is As the number of dogs people own goes up the number of cats people tend to own goes down Cats and dogs don t get along Few people with dogs have cats Few people with cats have dogs

The most common form of simple regression uses two ratio level variables a ratio level variable and an ordinal level variable a ratio level variable and a nominal level variable two ordinal level variables 1 point Which of the following correlation coefficients represents the strongest relationshi 0 75 34 52

A mass weighing 24 pounds attached to the end of a spring stretches it 4 inches Initially the mass is released from rest from a point 2 inches below the equilibrium position Find the equation motion Use g 32 ft s for the acceleration due to gravity x t 2 cos 9 81 cos 9 8 x ft 3 MY NOTES ASK YOUR TE

A survey of 22 retirees was taken Among other things the retirees were asked to report the age at which they retired Here are those 22 ages in years 35 44 46 48 51 52 58 59 61 61 62 63 64 64 65 65 67 72 73 74 75 78 Send data to calculator Frequency 10 8 6 00 4 2 0 30 Send data to Excel 40 3 4 50 Age in years Answer the questions below 60 a For these data which measures of central tendency take more than one value Choose all that apply b Suppose that the measurement 78 the largest measurement in the data set were replaced by 85 Which measures of central tendency would be affected by the change Choose all that apply c Suppose that starting with the original data set the largest measurement were removed Which measures of central tendency would be changed from those of the original data set Choose all that apply 9 70 80 Mean Median Mode ONone of these measures Mean Median Mode ONone of these measures Mean Median OMode None of these measures

In a survey conducted by a reputable marketing agency 227 of 1000 adults 19 years of age or older confessed to bringing and using their cell phone every trip to the bathroom confessions included texting and answering phone calls Complete parts a through f below Click here to view the standard normal distribution table page 1 Click here to view the standard normal distribution table page 2 The population to all its with a voi photo OB The population is the Type a whole number OC The population is all adults D The population is all adults 19 years of age or older b What is the variable of interest in this study Is it qualitative or quantitative The variable of interest is adults 19 years of age or older This variable is

A survey of 2275 adults in a certain large country aged 18 and older conducted by a reputable polling organization found that 415 have donated blood in the past two years Complete parts a through c below Click here to view the standard normal distribution table page 1 Click here to view the standard normal distribution table page 2 of the population size Round to three decimal places as needed c Construct and interpret a 90 confidence interval for the population proportion of adults in the country who have donated blood in the past two years Select the correct choice below and fill in any answer boxes within your choice Type integers or decimals rounded to three decimal places as needed Use ascending order OA There is a probability the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between and B We are confident the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between and

In a random sample of 49 audited estate tax returns it was determined that the mean amount of additional tax owed was 3440 with a standard deviation of 2569 Construct and interpret a 90 confidence interval for the mean additional amount of tax owed for estate tax returns Click here to view the standard normal distribution table page 1 Click here to view the standard normal distribution table page 2 Click here to view the table of critical t values Find and interpret a 90 confidence interval for the mean additional amount of tax owed for estate tax returns Select the correct choice below and fill in the answer boxes to complete your choice Use ascending order Round to the nearest dollar as needed O A There is a 90 probability that the mean additional tax owed is between B One can be 90 confident that the mean additional tax owed is between C 90 of taxes owed for estate tax returns are between and and and

In a survey of 1018 adults a polling agency asked When you retire do you think you will have enough money to live comfortably or not Of the 1018 surveyed 531 stated that they were worried about having enough money to live comfortably in retirement Construct a 95 confidence interval for the proportion of adults who are worried about having enough money to live comfortably in retirement Click here to view the standard normal distribution table page 1 Click here to view the standard normal distribution table page 2 Click here to view the table of critical t values Click here to view the table of critical values of the chi square distribution Select the correct choice below and fill in the answer boxes to complete your choice Use ascending order Round to three decimal places as needed OA 95 of the population lies in the interval between and OB There is a 95 probability that the true proportion of worried adults is between OC There is 95 confidence that the true proportion of worried adults is between and and

A simple random sample of size n 250 individuals who are currently employed is asked if they work at home at least once per week Of the 250 employed individuals surveyed 42 responded that they did work at home at least once per week Construct a 99 confidence interval for the population proportion of employed individuals who work at home at least once per week The lower bound is Round to three decimal places as needed

A simple random sample of size n 17 is drawn from a population that is normally distributed The sample mean is found to be x 59 and the sample standard deviation is found to be s 13 Construct a 95 confidence interval about the population mean The lower bound is The upper bound is Round to two decimal places as needed

a The standard normal curve is graphed below Shade the region under the standard normal curve to the left of z 0 00 0 4 M 0 3 0 2 0 1 X b Use this table or the ALEKS calculator to find the area under the standard normal curve to the left of z z 0 00 Give your answer to four decimal places for example 0 1234 03 Aa K

Determine the t value in each of the cases Click the icon to view the table of areas under the t distribution a Find the t value such that the area in the right tail is 0 01 with 27 degrees of freedom 2 473 Round to three decimal places as needed b Find the t value such that the area in the right tail is 0 005 with 16 degrees of freedom Round to three decimal places as needed

A national survey of 2500 adult citizens of a nation found that 22 dreaded Valentine s Day The margin of error for the survey was 1 4 percentage points with 90 confidence Explain what this means Which statement below is the best explanation Select all that apply A There is 90 confidence that the proportion of the adult citizens of the nation that did not dread Valentine s Day is between 0 766 and 0 794 B There is 90 confidence that 22 of the adult citizens of the nation dreaded Valentine s Day C There is a 90 probability that the proportion of the adult citizens of the nation that dreaded Valentine s Day is between 0 766 and 0 794 D There is 90 confidence that the proportion of the adult citizens of the nation that dreaded Valentine s Day is between 0 206 and 0 234 E In 90 of samples of adult citizens of the nation the proportion that dreaded Valentine s Day is between 0 206 and 0 234 F There is 88 6 to 91 4 confidence that 22 of the adult citizens of the nation dreaded Valentine s Day

1 As accounts manager in your company you classify 21 of the customers as good credit and the rest as risky credit depending on their credit rating Customers in the risky category allow their accounts to go overdue 62 of the time on average whereas those in the good category allow their accounts o go overdue only 5 of the time Let R An account is risky credit D An account is overdue Fill in the following values no calculation necessary also no partial credit 0 25 each a P DIR b P DIR c P D IR d P R P DNR 031

In a survey of 2035 adults in a certain country conducted during a period of economic uncertainty 66 thought that wages paid to workers in industry were too low The margin of error was 6 percentage points with 90 confidence F parts a through d below which represent a reasonable interpretation of the survey results For those that are not reasonable explain the flaw b We are 84 to 96 confident 66 of adults in the country during the period of economic uncertainty felt wages paid to workers in industry were too low Is the interpretation reasonable OA The interpretation is reasonable B The interpretation is flawed The interpretation provides no interval about the population proportion C The interpretation is flawed The interpretation indicates that the level of confidence is varying D The interpretation is flawed The interpretation suggests that this interval sets the standard for all the other intervals which is not true

at the Battle of Hastings The respective bids in thousands of dollars placed by the 20 bidders were as follows 3 7 11 12 12 12 16 17 17 18 18 18 19 19 21 21 21 22 22 24 Send data to calculator Send data to Excel Frequency 8 6 4 2 0 0 5 15 Bid in thousands of dollars Answer the questions below 4 10 a Which measures of central tendency do not exist for this data set Choose all that apply b Suppose that the measurement 24 the largest measurement in the data set were replaced by 38 Which measures of central tendency would be affected by the change Choose all that apply 8 c Suppose that starting with the original data set the largest measurement were removed Which measures of central tendency would be changed from those of the original data set Choose all that apply 20 25 Mean Median Mode OAll of these measures exist Mean OMedian Mode ONone of these measures Mean Median Mode None of these measures

1 In circle A below which of the following is not true EF is a chord b CB is a tangent line BA is a diameter a C d AD is a radius B D A F C E

19 of all college students volunteer their time Is the percentage of college students who are volunteers different for students receiving financial aid Of the 376 randomly selected students who receive financial aid 68 of them volunteered their time What can be concluded at the a 0 10 level of significance a For this study we should use Select an answer b The null and alternative hypotheses would be Ho Select an answer H Select an answer c The test statistic d The p value e The p value is a f Based on this we should g Thus the final conclusion is that please enter a decimal Please enter a decimal please show your answer to 3 decimal places Please show your answer to 4 decimal places Select an answer the null hypothesis The data suggest the population proportion is not significantly different from 19 at a 0 10 so there is sufficient evidence to conclude that the percentage of financial aid recipients who volunteer is equal to 19 The data suggest the population proportion is not significantly different from 19 at a 0 10 so there is insufficient evidence to conclude that the percentage of financial aid recipients who volunteer is different from 19 The data suggest the populaton proportion is significantly different from 19 at a 0 10 so there is sufficient evidence to conclude that the percentage of financial aid recipients who volunteer is different from 19

Suppose the Humane Society claims that 30 of U S households own cats You believe your community is different than the U S percentage To test the claim you take a simple random sample of 300 households and find that 33 own cats Test at 10 significance Round to the fourth as needed Requirements part 1 Select an answer Requirements part 2 Select an answer Ho Select an answer HA Select an answer Test Statistic Select an answer Select an answer P value Did something significant happen Select an answer Select the Decision Rule Select an answer 0 There Select an answer Select an answer enough evidence to conclude 0

A researcher claims that exactly 40 of all adults in the U S use their cell phone for most of their online browsing You believe that the true proportion is different To test this you take a simple random sample of 200 adults in the U S and find that 37 of them use their phone for most of their online browsing Test at 5 significance Round to the fourth as needed What s the minimum population size required How many successes were there Ho Select an answer HA Select an answer Test Statistic Select an answer Select an answer P value Did something significant happen Select an answer Select the Decision Rule Select an answer 0 There Select an answer Select an answer enough evidence to conclude 0 Build a 95 confidence interval and decide if you can conclude the same Use your calculator to do this and round to the fourth decimal place Can we conclude the same as our Hypothesis Test because the true proportion of U S adults that use their cell phones for most of their online browsing Select an answer 0

Answer true or false for the following statement x x is an odd integer 12 x 24 13 15 17 21 23 Choose the correct answer below OA This statement is true All of the odd integers between 12 and 24 are listed in ascending order OB This statement is true If you list all of the integers from 12 to 24 all of these numbers will be included i list OC This statement is false The set of integers includes negative numbers too There should be a total of te integers in the set 4 OD This statement is false There is one missing odd integer in the set which is 19

Suppose Kendra Gallegos has appointments with 9 potential customers Kendra will be ecstatic if all 9 of these potential customers decide to make a purchase from her Of course in sales there are no guarantees How many different sets of customers may place an order with Kendra Hint Each set of customers is a subset of the origina set of 9 customers The set has subsets Type a whole number

Describe the intersection and union of sets How do they differ Choose the correct answer below A The intersection of sets A and B is the set of all elements belonging to set A to set B or to both sets The union of sets A and B is the set of all elements common to both sets B The intersection of sets A and B is the set of all elements common to both sets The union of sets A and B the set of all elements belonging to only set A or only to set B OC The intersection of sets A and B is the set of all elements common to both sets The union of sets A and B the set of all elements belonging to set A to set B or to both sets D The intersection of sets A and B is the set of all elements belonging to only set A or only to set B The union of sets A and B is the set of all elements common to both sets

Use the Venn diagram to determine the number of elements in the following set AnB The number of elements in the set is Type a whole number SAG A 22 10 19 B

Let A 1 2 3 3 1 4 7 Tell whether the statement is true or false 7EA Is the statement true or false O True False

Insert nor U to make the statement true 4 8 9 13 8 9 15 19 8 9 4 8 9 13 8 9 15 19 8 9

The mean height of an adult giraffe is 17 feet Suppose that the distribution is normally distributed with standard deviation 0 8 feet Let X be the height of a randomly selected adult giraffe Round all answers to 4 decimal places where possible a What is the distribution of X X N b What is the median giraffe height ft c What is the Z score for a giraffe that is 20 foot tall d What is the probability that a randomly selected giraffe will be shorter than 17 9 feet tall e What is the probability that a randomly selected giraffe will be between 16 8 and 17 7 feet tall f The 70th percentile for the height of giraffes is ft

The amount of time that people spend at Grover Hot Springs is normally distributed with a mean of 63 minutes and a standard deviation of 17 minutes Suppose one person at the hot springs is randomly chosen Let X the amount of time that person spent at Grover Hot Springs Round all answers to 4 decimal places where possible a What is the distribution of X X NO b Find the probability that a randomly selected person at the hot springs stays longer then 76 minutes c The park service is considering offering a discount for the 8 of their patrons who spend the least time at the hot springs What is the longest amount of time a patron can spend at the hot springs and still receive the discount minutes d Find the Inter Quartile Range IQR for time spent at the hot springs Q1 minutes minutes Q3 IQR Hint minutes Helpful videos

A survey of 83 randomly selected homeowner mean amount of money spent per month on h

The percent of fat calories that a person in America consumes each day is normally distributed with a mean of about 35 and a standard deviation of 9 Suppose that one individual is randomly chosen Let X percent of fat calories Round all answers to 4 decimal places if where possible a What is the distribution of X X NO b Find the probability that a randomly selected fat calorie percent is more than 32 c Find the minimum number for the upper quarter of percent of fat calories Hint

A study was conducted on students from a particular high school over the last 8 years The following information was found regarding standardized tests used for college admitance Scores on the SAT test are normally distributed with a mean of 1100 and a standard deviation of 206 Scores on the ACT test are norma distributed with a mean of 21 9 and a standard deviation of 4 9 It is assumed that the two tests measure the same aptitude but use different scales If a student gets an SAT score that is the 71 percentile find the actual SAT score SAT score Round answer to a whole number What would be the equivalent ACT score for this student ACT score Round answer to 1 decimal place If a student gets an SAT score of 1347 find the equivalent ACT score ACT score Round answer to 1 decimal place

Adult men have an average height of 69 0 inches with a standard deviation of 2 8 inches Find the height of a man with a z score of 0 64 Round your answer to one decimal place inches

On a planet far far away from Earth IQ of the ruling species is normally distributed with a mean of 115 and a standard deviation of 17 Suppose one individual is randomly chosen Let X IQ of an individual a What is the distribution of X X N b Find the probability that a randomly selected person s IQ is over 75 decimal places Round your answer to 4 c A school offers special services for all children in the bottom 4 for IQ scores What is the highest IQ score a child can have and still receive special services Round your answer to 2 decimal places d Find the Inter Quartile Range IQR for IQ scores Round your answers to 2 decimal places Q1 Q3 IQR Hint

Suppose the mean income of firms in the indu industry are distributed normally what is the to four decimal places

Consider the fallbang quadratic x Y 2 5 1 3 5 0 1 2 3 4 Find the equation of the function of the specified type that is the best fit for the given data y x 0 5x8 Check the degree of your polynomial Plot the data and the equation 20 10 10 B 8 5 5 20 2 5 14 O y 20 10 1 y 20 10 10 20 2 O 1 Exactly 20 10 10 20 1 3

Brain Mass g 700 600 500 400 O 300 200 100 0 50 100 150 200 250 300 350 400 Gestation Days 2 What type of correlation appears to exist 5 points between the gestation period and the brain mass O A negative linear correlation O A positive linear correlation 3 What is the correct interpretation of this relationship In general as the gestation period decreases the brain mass increases 5 points A greater brain mass leads to a longer gestation period

Only 17 of registered voters voted in the last election Will voter participation change for the upcoming election Of the 376 randomly selected registered voters surveyed 60 of them will vote in the upcoming election What can be concluded at the a 0 01 level of significance a For this study we should use Select an answer b The null and alternative hypotheses would be Ho Select an answer H Select an answer please enter a decimal Please enter a decimal please show your answer to 3 decimal places c The test statistic d The p value e The p value is a f Based on this we should Select an answer the null hypothesis g Thus the final conclusion is that Please show your answer to 4 decimal places The data suggest the populaton proportion is significantly different from 17 at a 0 01 so there is statistically significant evidence to conclude that the the percentage of all registered voters who will vote in the upcoming election will be different from 17 The data suggest the population proportion is not significantly different from 17 at a 0 01 so there is statistically significant evidence to conclude that the percentage of registered voters who will vote in the upcoming election will be equal to 17 The data suggest the population proportion is not significantly different from 17 at a 0 01 so there is statistically insignificant evidence to conclude that the percentage of registered voters who will vote in the upcoming election will be different from 17

Writing com has a beginning inventory of 16 sets of pens at a cost of 2 12 each During the year Writing com purchased 8 sets at 2 15 9 sets at 2 25 14 sets at 3 05 and 13 sets at 3 20 By the end of the year 29 sets were sold a Calculate the number of pen sets in stock Ending inventory b Calculate the cost of ending inventory under LIFO FIFO and weighted average methods Note Round your intermediate calculation and final answers to the nearest cent LIFO FIFO Weighted average

A survey of Mount Everest climbers in 2021 shows that 29 of those surveyed have successfully set foot on the summit a A random sample of 12 climbers was taken The number of climbers who successfully set foot on the summit can be modelled by a binomial distribution i State two assumptions made in order for this model to be valid ii Find the probability that at least four people from the sample made a successful summit climb b From a random sample of n climbers the probability that at least one of them made a successful summit climb in 2021 is greater than 0 995 Determine the least possible value of n 3 4

9 nts TB MC Qu 08 54 Static At the end of the At the end of the current accounting period Ringgold

Any athlete who fails the Enormous State University s women s soccer fitness test is automatically dropped from the team Last year Mona Header failed the test but claimed that this was due to the early hour The fitness test is traditionally given at 5 AM on a Sunday morning In fact a study by the ESU Physical Education Department suggested that 48 of athletes fit enough to play on the team would fail the soccer test although no unfit athlete could possibly pass the test It also estimated that 39 of the athletes who take the test are fit enough to play soccer Assuming these estimates are correct what is the probability that Mona was justifiably dropped Round your answer to four decimal places 0 4835 X

Suppose that it snows in Greenland an average of once every 25 days and when it does glaciers have a 30 chance of growing When it does not snow in Greenland glaciers have only a 5 chance of growing What is the probability that it is snowing in Greenland when glaciers are growing Round your answer to four decimal places