Deck 8: Confidence Intervals

Question 1

A confidence interval increases in width as

A)The level of confidence increases
B)n decreases
C)s increases
D)All of the above

Answer 1

D

Question 2

When the sample size and sample standard deviation remain the same,a 99% confidence interval for a population mean,µ will be narrower than the 95% confidence interval for µ.

Answer 2

False

Question 3

The standard error of the sample mean is s/ $\sqrt{n}$ .

Answer 3

True

Question 4

When determining the sample size n,if the value found for n is 79.2,we would choose to sample 79 observations.

Question 5

As standard deviation increases,samples size _____________ to achieve a specified level of confidence.

A)Increases
B)Decreases
C)Remains the same

Question 6

When the population is normally distributed and the population standard deviation $\sigma$ is unknown,then for any sample size n,the sampling distribution of is based on the z distribution.

Question 7

The t distribution always has n degrees of freedom.

Question 8

Assuming the same level of significance $\alpha$ ,as the sample size increases,the value of t $\alpha$ /2approaches the value of z $\alpha$ /2.

Question 9

When determining the sample size,if the value found is not an integer initially,the next highest integer value will ____________ be chosen.

A)Always
B)Sometimes
C)Never

Question 10

When the level of confidence and sample size remain the same,a confidence interval for a population proportion p will be narrower when is larger than when is smaller.

Question 11

First a 90% confidence interval is constructed from a sample size of 100.Then,for the same identical data,a 92% confidence interval is constructed.The width of the 90% interval is wider than the 92% confidence interval.

Question 12

When solving for the sample size needed to compute a 95% confidence interval for a population proportion "p",having a given error bound "B",we choose a value of that makes as small as reasonably possible.

Question 13

When the margin of error is added to and subtracted from the sample mean an interval is formed that will contain $\mu$ with probability of (1 - $\alpha$ ).

Question 14

When constructing a confidence interval for a sample proportion,the t distribution is appropriate if the sample size is small.

Question 15

When the level of confidence and the sample size remain the same,a confidence interval for a population mean µ will be wider,when the sample standard deviation s is small than when s is large.

Question 16

When the level of confidence and sample proportion remain the same,a confidence interval for a population proportion p based on a sample of n = 100 will be wider than a confidence interval for p based on a sample of n = 400.

Question 17

When constructing a confidence interval for a population mean,if a population is normally distributed and a small sample is taken,then the distribution of is based on _____ distribution.

A)z
B)t
C)Neither
D)Both A and B

Question 18

The width of a confidence interval will be:

A)Narrower for 99% confidence than 95% confidence.
B)Wider for a sample size of 100 than for a sample size of 50.
C)Narrower for 90% confidence than 95% confidence.
D)Wider when the sample standard deviation (s)is small than when s is large.

Question 19

When the level of confidence and sample standard deviation remain the same,a confidence interval for a population mean based on a sample of n = 100 will be narrower than a confidence interval for a population mean based on a sample of n = 50.

Question 20

The t distribution approaches the _______________ as the sample size ___________.

A)Binomial,increases
B)Binomial,decreases
C)Z,decreases
D)Z,increases

Question 21

When the level of confidence and sample size remain the same,a confidence interval for a population proportion p will be ______________ when is larger than when is smaller.

A)Wider
B)Narrower
C)Neither A nor B,they will be the same

Question 22

A Research and Development Laboratory researcher for a paint company is measuring the level a certain chemical contained in a certain type of paint.If the paint contains too much of this chemical,the quality of the paint will be compromised.On the average,each can of paint contains 10% of the chemical,How many cans of paint should the sample contain if the researcher wants to be 98% certain of being within 1% of the true proportion of this chemical?

A)4887
B)1107
C)26
D)645

Question 23

In a manufacturing process a random sample of 9 bolts manufactured has a mean length of 3 inches with a variance of .09.What is the 90% confidence interval for the true mean length of the bolt?

A)2.8355 to 3.1645
B)2.5065 to 3.4935
C)2.4420 to 3.5580
D)2.8140 to 3.8160
E)2.9442 to 3.0558

Question 24

When solving for the sample size needed to compute a 95% confidence interval for a population proportion "p",having a given error bound "B",we choose a value of that:

A)Makes
B)Makes
C)Makes
D)Makes
E)Both B and D are correct

Question 25

In a manufacturing process,we are interested in measuring the average length of a certain type of bolt.Past data indicates that the standard deviation is .25 inches.How many bolts should be sampled in order to make us 95% confident that the sample mean bolt length is within .02 inches of the true mean bolt length?

A)25
B)49
C)423
D)601
E)1225

Question 26

When the sample size and the sample proportion remain the same,a 90% confidence interval for a population proportion p will be ______________ the 99% confidence interval for p.

A)Wider than
B)Narrower than
C)Equal to

Question 27

In a manufacturing process a random sample of 36 bolts manufactured has a mean length of 3 inches with a standard deviation of .3 inches.What is the 99% confidence interval for the true mean length of the bolt?

A)2.902 to 3.098
B)2.884 to 3.117
C)2.865 to 3.136
D)2.228 to 3.772
E)2.685 to 3.698

Question 28

When the level of confidence and sample proportion remain the same,a confidence interval for a population proportion p based on a sample of n = 100 will be ______________ a confidence interval for p based on a sample of n = 400.

A)Wider than
B)Narrower than
C)Equal to

Question 29

When the level of confidence and the sample size remain the same,a confidence interval for a population mean µ will be ________________,when the sample standard deviation s is small than when s is large.

A)Wider
B)Narrower
C)Neither A nor B,they will be the same

Question 30

Assuming the same level of significance $\alpha$ ,as the sample size increases,the value of t_a/2 _____ approaches the value of .

A)Always
B)Sometimes
C)Never

Question 31

The width of a confidence interval will be:

A)Narrower for 98% confidence than for 90% confidence.
B)Wider for a sample size of 64 than for a sample size of 36.
C)Wider for a 99% confidence than for 95% confidence.
D)Narrower for sample size of 25 than for a sample size of 36.
E)None of the above.

Question 32

When the population is normally distributed,population standard deviation $\sigma$ is unknown,and the sample size is n = 15;the confidence interval for the population mean µ is based on:

A)The z (normal)distribution
B)The t distribution
C)The Binomial distribution
D)The Poisson distribution
E)None of the above

Question 33

There is little difference between the values of t _{$\alpha$ /2} and z _{$\alpha$ /2} when:

A)The sample size is small
B)The sample size is large
C)The sample mean is small
D)The sample mean is large
E)The sample standard deviation is small

Question 34

The internal auditing staff of a local manufacturing company performs a sample audit each quarter to estimate the proportion of accounts that are current (between 0 and 60 days after billing).The historical records show that over the past 8 years 70 percent of the accounts have been current.Determine the sample size needed in order to be 99% confident that the sample proportion of the current customer accounts is within .03 of the true proportion of all current accounts for this company.

A)1842
B)1548
C)897
D)632
E)1267

Question 35

Which of the following is an advantage of confidence interval estimate over a point estimate for a population parameter?

A)Interval estimates are more precise than point estimates.
B)Interval estimates are less accurate than point estimates.
C)Interval estimates are both more accurate and more precise than point estimates.
D)Interval estimates take into account the fact that the statistic being used to estimate the population parameter is a random variable.

Question 36

When the sample size and sample standard deviation remain the same,a 99% confidence interval for a population mean,µ will be _________________ the 95% confidence interval for µ.

A)Wider than
B)Narrower than
C)Equal to

Question 37

The internal auditing staff of a local manufacturing company performs a sample audit each quarter to estimate the proportion of accounts that are delinquent (more than 90 days overdue).For this quarter,the auditing staff randomly selected 400 customer accounts and found that 80 of these accounts were delinquent.What is the 95% confidence interval for the proportion of all delinquent customer accounts at this manufacturing company?

A).1608 to .2392
B).1992 to .2008
C).1671 to .2329
D).1485 to .2515
E).1714 to .2286

Question 38

When the level of confidence and sample standard deviation remain the same,a confidence interval for a population mean based on a sample of n = 100 will be ______________ a confidence interval for a population mean based on a sample of n = 50.

A)Wider than
B)Narrower than
C)Equal to

Question 39

When a confidence interval for a population proportion is constructed for a sample size n = 30 and the value of = .4,the interval is based on:

A)The z distribution
B)The t distribution
C)The exponential distribution
D)The Poisson distribution
E)None of the above

Question 40

In a manufacturing process a random sample of 9 bolts manufactured has a mean length of 3 inches with a standard deviation of .3 inches.What is the 95% confidence interval for the true mean length of the bolt?

A)2.804 to 3.196
B)2.308 to 3.692
C)2.770 to 3.231
D)2.412 to 3.588
E)2.814 to 3.186

Question 41

Research has been conducted that studies the role that the age of workers has in determining the hours per month spent on personal tasks.A sample of 1,686 adults were observed for one month.The data are: Construct a 98% confidence interval for the mean hours spent on personal tasks for 25-44 year olds.

A)[3.96 4.12]
B)[3.97 4.11]
C)[3.98 4.10]
D)[2.16 5.92]
E)[3.95 4.13]

Question 42

Health insurers and the federal government are both putting pressure on hospitals to shorten the average length of stay (LOS)of their patients.In 1996,the average LOS for non-heart patient was 4.6 days.A random sample of 20 hospitals in one state had a mean LOS for non-heart patients in 2000 of 3.8 days and a standard deviation of 1.2 days.Calculate a 95% confidence interval for the population mean LOS for non-heart patients in the state's hospitals in 2000.

A)[3.24 4.36]
B)[3.67 3.93]
C)[3.34 4.26]
D)[3.38 4.22]
E)[3.27 4.33]

Question 43

In a manufacturing process,we are interested in measuring the average length of a certain type of bolt.Based on a preliminary sample of 9 bolts,the sample standard deviation is .3 inches.How many bolts should be sampled in order to make us 95% confident that the sample mean bolt length is within .02 inches of the true mean bolt length?

A)865
B)80
C)1470
D)3989
E)1197

Question 44

Unoccupied seats on flights cause airlines to lose revenue.Suppose a large airline wants to estimate its average number of unoccupied seats per flight over the past year.225 flight records are randomly selected and the number of unoccupied seats is noted with a sample mean of 11.6 seats and a standard deviation of 4.1 seats.How many flights should we select if we wish to estimate $\mu$ to within 2 seats and be 95% confident?

A)130
B)65
C)33
D)17
E)12

Question 45

The coffee/soup machine at the local bus station is supposed to fill cups with 6 ounces of soup.Ten cups of soup are brought with results of a mean of 5.93 ounces and a standard deviation of 0.13 ounces.How large a sample of soups would we need to be 95% confident that the sample mean is within 0.03 ounces of the population mean?

A)97
B)96
C)73
D)62
E)10

Question 46

A company is interested in estimating ,the mean number of days of sick leave taken by its employees.The firm's statistician randomly selects 100 personnel files and notes the number of sick days taken by each employee.The sample mean is 12.2 days and the sample standard deviation is 10 days.Calculate a 93% confidence interval for ,the mean number of days of sick leave.

A)[10.725 13.675]
B)[10.390 14.010]
C)[12.019 12.381]
D)[12.053 12.348]
E)[11.735 12.665]

Question 47

Health insurers and the federal government are both putting pressure on hospitals to shorten the average length of stay (LOS)of their patients.In 1996,the average LOS for non-heart patient was 4.6 days.A random sample of 20 hospitals in one state had a mean LOS for non-heart patients in 2000 of 3.8 days and a standard deviation of 1.2 days.How large a sample of hospitals would we need to be 99% confident that the sample mean is within 0.5 days of the population mean?

A)3
B)7
C)32
D)48
E)96

Question 48

At the end of 1990,1991,and 1992 the average prices of a share of stock in a money market portfolio were $34.83,$34.65 and $31.26 respectively.To investigate the average share price at the end of 1993,a random sample of 30 stocks was drawn and their closing prices on the last trading day of 1993 were observed with a mean of 33.583 and a standard deviation of 19.149.Estimate the average price of a share of stock in the portfolio at the end of 1993 with a 90% confidence interval.

A)[27.832 39.334]
B)[26.732 40.434]
C)[32.514 34.651]
D)[32.533 34.633]
E)[32.269 34.897]

Question 49

A local company makes a candy that is supposed to weigh 1.00 ounces.A random sample of 25 pieces of candy produces a mean of 0.996 ounces with a standard deviation of 0.004 ounces.Construct a 98% confidence interval for the mean weight of all such candy.

A)[0.9645 1.0275]
B)[0.9956 0.9964]
C)[0.9860 1.0060]
D)[0.9940 0.9980]
E)[0.9942 0.9978]

Question 50

A local company makes a candy that is supposed to weigh 1.00 ounces.A random sample of 25 pieces of candy produces a mean of 0.996 ounces with a standard deviation of 0.004 ounces.How many pieces of candy must we sample if we want to be 99% confident that the sample mean is within 0.001 ounces of the true mean?

A)126
B)124
C)107
D)12
E)6

Question 51

The state highway department is studying traffic patterns on one of the busiest highways in the state.As part of the study,the department needs to estimate the average number of vehicles that pass an intersection each day.A random sample of 64 days gives us a sample mean of 14,205 cars and a sample standard deviation of 1,010 cars.What is the 92% confidence interval estimate of $\mu$ ,the mean number of cars passing the intersection?

A)[12,438 15,972]
B)[14,028 14,382]
C)[12,189 14,221]
D)[13,984 14,426]
E)[14,183 14,227]

Question 52

Unoccupied seats on flights cause airlines to lose revenue.Suppose a large airline wants to estimate its average number of unoccupied seats per flight over the past year.225 flight records are randomly selected and the number of unoccupied seats is noted with a sample mean of 11.6 seats and a standard deviation of 4.1 seats.Calculate a 90% confidence interval for ,the mean number of unoccupied seats per flight during the past year.

A)[4.86 18.34]
B)[11.25 11.95]
C)[11.57 11.63]
D)[11.15 12.05]
E)[11.30 12.20]

Question 53

In a random sample of 651 computer scientists who subscribed to a web-based daily news update,it was found that the average salary was $46,816 with a standard deviation of $12,557.Calculate a 91% confidence interval for the mean salary of computer scientists.

A)[$25,469 $68,163]
B)[$46,592 $47,040]
C)[$46,157 $47,475]
D)[$46,783 $46,849]
E)[$45,979 $47,653]

Question 54

An environmental group at a local college is conducting independent tests to determine the distance a particular make of automobile will travel while consuming only 1 gallon of gas.A sample of five cars is tested and a mean of 28.2 miles is obtained.Assuming that the standard deviation is 2.7 miles,find the 95% confidence interval for the mean distance traveled by all such cars using 1 gallon of gas.

A)[26.16 30.24]
B)[20.70 35.70]
C)[24.85 31.55]
D)[26.70 29.70]
E)[25.83 30.57]

Question 55

A psychologist is collecting data on the time it takes to learn a certain task.For 50 randomly selected adult subjects,the sample mean is 16.40 minutes and the sample standard deviation is 4.00 minutes.Construct the 95% confidence interval for the mean time required by all adults to learn the task.

A)[8.56 24.24]
B)[15.47 17.33]
C)[16.24 16.56]
D)[15.29 17.51]
E)[17.12 48.48]

Question 56

The state highway department is studying traffic patterns on one of the busiest highways in the state.As part of the study,the department needs to estimate the average number of vehicles that pass an intersection each day.A random sample of 64 days gives us a sample mean of 14,205 cars and a sample standard deviation of 1,010 cars.After calculating the confidence interval,the highway department officials decide that the precision is too low for their needs.They feel the precision should be 300 cars.Given this precision,and needing to be 99% confident,how many days do they need to sample?

A)109
B)76
C)75
D)62
E)9

Question 57

The coffee/soup machine at the local bus station is supposed to fill cups with 6 ounces of soup.Ten cups of soup are brought with results of a mean of 5.93 ounces and a standard deviation of 0.13 ounces.Construct a 99% confidence interval for the true machine-fill amount.

A)[5.888 5.972]
B)[5.814 6.046]
C)[5.716 6.144]
D)[5.824 6.036]
E)[5.796 6.064]

Question 58

A company is interested in estimating ,the mean number of days of sick leave taken by its employees.The firm's statistician randomly selects 100 personnel files and notes the number of sick days taken by each employee.The sample mean is 12.2 days and the sample standard deviation is 10 days.How many personnel files would the director have to select in order to estimate $\mu$ to within 2 days with a 99% confidence interval?

A)2
B)13
C)136
D)165
E)166

Question 59

In a study of factors affecting soldiers' decisions to reenlist,320 subjects were measured for an index of satisfaction and the sample mean is 28.8 and the sample standard deviation is 7.3.Use the given sample data to construct the 98% confidence interval for the population mean.

A)[27.85 29.75]
B)[27.96 29.64]
C)[11.82 45.78]
D)[28.75 28.85]
E)[28.60 29.00]

Question 60

The U.S.Department of Health and Human Services collected sample data for 772 males between the ages of 18 and 24.That sample group has a mean height of 69.7 inches with a standard deviation of 2.8 inches.Find the 99% confidence interval for the mean height of all males between the ages of 18 and 24.

A)[63.19 76.21]
B)[62.49 76.91]
C)[69.65 69.75]
D)[69.47 69.93]
E)[69.44 69.96]

Question 61

Recently,a case of food poisoning was traced to a particular restaurant chain.The source was identified and corrective actions were taken to make sure that the food poisoning would not reoccur.Despite the response from the restaurant chain,many consumers refused to visit the restaurant for some time after the event.A survey was conducted three months after the food poisoning occurred with a sample of 319 patrons contacted.Of the 319 contacted,29 indicated that they would not go back to the restaurant because of the potential for food poisoning Construct a 95% confidence interval for the true proportion of the market who still refuse to visit any of the restaurants in the chain three months after the event.

A)[.059 .122]
B)[.090 .091]
C)[.000 .196]
D)[.240 .339]
E)[.118 .244]

Question 62

A sociologist develops a test designed to measure a person's attitudes about disabled people,and 16 randomly selected subjects are given the test.Their mean score is 71.2 with a standard deviation of 10.5.Construct the 99% confidence interval for the mean score of all subjects.

A)[40.26 102.14]
B)[63.46 78.94]
C)[60.66 81.74]
D)[64.44 77.96]
E)[63.21 79.19]

Question 63

A manufacturer of dodge balls uses a machine to inflate its new balls to a pressure of 13.5 pounds ( = 0.1).When the machine is properly calibrated,the mean inflation pressure s 13.5 pounds,but uncontrollable factors can cause the pressure of individual dodge balls to vary.For quality control purposes,the manufacturer wishes to estimate the mean inflation pressure to within 0.025 pounds of its true value with a 99% confidence.What sample size should be used?

A)677
B)107
C)35
D)27
E)11

Question 64

In the construction of a confidence interval,as the confidence level required in estimating the mean increases,the width of the confidence interval ______________.

A)Stays the same
B)Decreases
C)Increases

Question 65

The Ohio Department of Agriculture tested 203 fuel samples across the state in 1999 for accuracy of the reported octane level.For premium grade,14 out of 105 samples failed (they didn't meet ASTM specification and the FTC Octane posting rule).Find a 99% confidence interval for the true population proportion of premium grade fuel-quality failures.

A)[.045 .221]
B)[.068 .198]
C)[.023 .115]
D)[.047 .219]
E)[.100 .276]

Question 66

At a sobriety checkpoint the sheriff's department screened 676 drivers and 6 were arrested for DWI.Find the 92% confidence interval for the true proportion of drivers who were DWI that evening.

A)[0.000 0.027]
B)[0.003 0.015]
C)[0.902 0.938]
D)[0.000 0.076]
E)[0.006 0.030]

Question 67

An environmental group at a local college is conducting independent tests to determine the distance a particular make of automobile will travel while consuming only 1 gallon of gas.A sample of five cars is tested and a mean of 28.2 miles is obtained.How many cars should the environmental group test if they wish to estimate $\mu$ ,mean miles per 1 gallon,to within 0.5 miles and be 99% confident? Assume a population standard deviation of 2.7 miles.

A)25
B)124
C)194
D)618
E)619

Question 68

A federal bank examiner is interested in estimating the mean outstanding defaulted loans balance of all defaulted loans over the last three years.A random sample of 20 defaulted loans yielded a mean of $67,918 with a standard deviation of $16,552.40.Calculate a 90% confidence interval for the mean balance of defaulted loans over the past three years.

A)[66,487 69,349]
B)[39,299 96,537]
C)[57,329 78,507]
D)[61,829 74,007]
E)[61,519 74,317]

Question 69

On a standard IQ test,the standard deviation is 15.How many random IQ scores must be obtained if we want to find the true population mean (with an allowable error of 0.5)and we want 97% confidence in the results?

A)4,239
B)283
C)212
D)131
E)66

Question 70

In a poll of 1,004 adults,93% indicated that restaurants and bars should refuse service to patrons who have had too much to drink.Construct the 90% confidence interval for the proportion of all adults who feel the same way.

A)[.078 .108]
B)[.914 .946]
C)[.920 .940]
D)[.917 .943]
E)[.910 .950]

Question 71

An experiment was conducted to determine the effectiveness of a method designed to remove oil wastes found in soil.Three contaminated soil samples were treated.After 95 days,the percentage of contamination removed from each soil sample was measured with a mean of 49.3% and a standard deviation of 1.5%.If we wished to narrow the boundary around $\mu$ for a 98% confidence interval to within 0.5%,how many soil samples should be in our experiment.

A)437
B)33
C)9
D)6
E)3

Question 72

An experiment was conducted to determine the effectiveness of a method designed to remove oil wastes found in soil.Three contaminated soil samples were treated.After 95 days,the percentage of contamination removed from each soil sample was measured with a mean of 49.3% and a standard deviation of 1.5%.Estimate the mean percentage of contamination removed at a 98% confidence level.

A)[48.36 50.24]
B)[43.27 55.33]
C)[47.29 51.31]
D)[47.88 50.72]
E)[46.47 52.13]

Question 73

In 1995,13,000 WWW users were surveyed and asked about their willingness to pay fees for access to websites.Of these,2,938 were definitely not willing to pay such fees.How large a sample is necessary to estimate the proportion of interest to within 2% in a 95% confidence interval?

A)18
B)307
C)1717
D)2000
E)2965

Question 74

In a survey of 308 adults,17% listed jewelry among the romantic gifts men want to receive.Construct the 98% confidence interval for the proportion of all adults who include jewelry among their responses.

A)[.025 .085]
B)[.169 .171]
C)[.120 .220]
D)[.140 .200]
E)[.050 .170]

Question 75

The Ohio Department of Agriculture tested 203 fuel samples across the state in 1999 for accuracy of the reported octane level.For premium grade,14 out of 105 samples failed (they didn't meet ASTM specification and the FTC Octane posting rule).How many samples would be needed to create a 99% confidence interval that is within 0.02 of the true proportion of premium grade fuel-quality failures?

A)4148
B)2838
C)1913
D)744
E)54

Question 76

To investigate the rate at which employees with cancer are fired or laid off,a telephone survey was taken of 100 cancer survivors who worked while undergoing treatment.Seven (7)were either fired or laid off due to their illness.Construct a 90% confidence interval for the true percentage of all cancer patients who are fired or laid off due to their illness.

A)[0.0000 0.2034]
B)[0.0371 0.1029]
C)[0.0039 0.1361]
D)[0.0278 0.1122]
E)[0.0078 0.1400]

Question 77

Recently,a case of food poisoning was traced to a particular restaurant chain.The source was identified and corrective actions were taken to make sure that the food poisoning would not reoccur.Despite the response from the restaurant chain,many consumers refused to visit the restaurant for some time after the event.A survey was conducted three months after the food poisoning occurred with a sample of 319 patrons contacted.Of the 319 contacted,29 indicated that they would not go back to the restaurant because of the potential for food poisoning.What sample size would be needed in order to be 99% confident that the sample proportion is within .02 of $\rho$ ,the true proportion of customers who refuse to go back to the restaurant?

A)14
B)38
C)129
D)1,371
E)1,777

Question 78

There is an average of 22.455 employees at 22 office furniture dealers in a major metropolitan area with a standard deviation of 18.52.Construct a 99% confidence interval for the true mean number of full-time employees at office furniture dealers.

A)[11.014 33.896]
B)[11.277 33.633]
C)[12.284 32.626]
D)[12.513 32.397]
E)[20.072 24.838]

Question 79

A botanist measures the heights of 16 seedlings and obtains a mean and standard deviation of 72.5 cm and 4.5 cm,respectively.Find the 95% confidence interval for the mean height of seedlings in the population form which the sample was selected.

A)[62.91 82.09]
B)[70.30 74.70]
C)[70.10 74.90]
D)[70.54 74.46]
E)[71.90 73.10]

Question 80

In 1995,13,000 WWW users were surveyed and asked about their willingness to pay fees for access to websites.Of these,2,938 were definitely not willing to pay such fees.Construct a 95% confidence interval for the proportion definitely unwilling to pay fees.

A)[0.286 0.302]
B)[0.219 0.233]
C)[0.220 0.232]
D)[0.212 0.241]
E)[0.214 0.245]