Question 1

When estimating sample size,a 90 percent confidence level will result in a smaller sample size than a 95 percent confidence level.

Accepted Answer

A) True 
 B)False

Question 2

In an application to estimate the mean number of miles that downtown employees commute to work roundtrip each day,the following information is given:   If the desired confidence level is 95 percent,the appropriate critical value is:

Accepted Answer

A) z = 1.96. 
B) t = 2.093. 
C) t = 2.086. 
D) .7826. 
A) z = 1.96. 
B) t = 2.093. 
C) t = 2.086. 
D) .7826.

Question 3

Twenty one (21)customers out of a simple random sample of 50 said that they came to the grocery store within one month after getting a card from the company.Based on the data,the marketing manager thinks that the number of total customers who would come in to the grocery store within one month is 4,200 because 10,000 cards were mailed.

Accepted Answer

A) True 
 B)False

Question 4

An emergency room in a hospital wants to determine the sample size needed for estimating their mean number of visits per day.If they want a 99 percent confidence level the correct critical value to use is 2.33.

Accepted Answer

A) True 
 B)False

Question 5

The standard deviation for the checking account balances is assumed known to be $357.50.Recently,a bank manager was interested in estimating the mean balance.To do this,she selected a random sample of 81 accounts and found a mean balance of $1,347.20.At a 95 percent confidence level,the lower limit for the confidence interval is $646.50.

Accepted Answer

A) True 
 B)False

Question 6

What are the disadvantages of using a small sample to estimate the population mean?

Accepted Answer

A small sample impacts the estimation of

Question 7

If the population is not normally distributed,the t-distribution cannot be used.

Accepted Answer

A) True 
 B)False

Question 8

The chamber of commerce in a beach resort town wants to estimate the proportion of visitors who are repeat visitors.From previous experience they believe the portion is not larger than 20 percent.They want to estimate the proportion to within ± 0.04 percentage points with 95 percent confidence.The sample size they should use is:

Accepted Answer

A) n = 601. 
B) n = 97. 
C) n = 10. 
D) n = 385. 
A) n = 601. 
B) n = 97. 
C) n = 10. 
D) n = 385.

Question 9

Past experience indicates that the variance in the time it takes for a "fast lube" operation to actually complete the lube and oil change for customers is 9.00 minutes.The manager wishes to estimate the mean time with 99 percent confidence and a margin of error of ± 0.50 minutes.Given this,what must the sample size be?

Accepted Answer

A) n = 239 
B) n = 2149 
C) n = 139 
D) n = 1245 
A) n = 239 
B) n = 2149 
C) n = 139 
D) n = 1245

Question 10

A random sample of n = 500 people was surveyed recently to determine an estimate for the proportion of people in the population who had attended at least some college.The estimate concluded that between 0.357 and 0.443 of the population had attended.Given this information,we can determine that the confidence level was approximately 95 percent.

Accepted Answer

A) True 
 B)False

Question 11

If a decision maker desires a small margin of error and a high level of confidence,it is certain that the required sample size will be quite large.

Accepted Answer

A) True 
 B)False

Question 12

A pilot sample is one that is used when a decision maker wishes to get an advance idea of what the mean of the population might be.

Accepted Answer

A) True 
 B)False

Question 13

To find a 98 percent confidence interval where the standard deviation is known,the correct z-value to use for the critical value is 2.33.

Accepted Answer

A) True 
 B)False

Question 14

If a manager believes that the required sample size is too large for a situation in which she desires to estimate the mean income of blue collar workers in a state,which of the following would lead to a reduction in sample size?

Accepted Answer

A) Reduce the level of confidence 
B) Allow a higher margin of error 
C) Somehow reduce the variation in the population 
D) All of the above. 
A) Reduce the level of confidence 
B) Allow a higher margin of error 
C) Somehow reduce the variation in the population 
D) All of the above.

Question 15

An analyst for a financial investment firm recently went through the effort to determine the required sample size for estimating the mean number of transactions per year for the clients of his firm.The calculations,which were based on a 95 percent confidence level and a margin of error of ± 3,gave a required sample size of 300.Given this information,the value used for the population standard deviation must have been about 26.5 transactions.

Accepted Answer

A) True 
 B)False

Question 16

The main purpose of a pilot sample in an application involving an estimate for a population mean is to determine what the margin of error will likely be.

Accepted Answer

A) True 
 B)False

Question 17

One way to reduce the margin of error in a confidence interval estimate is to lower the level of confidence.

Accepted Answer

A) True 
 B)False

Question 18

If a manager is interested in estimating the mean time customers spend shopping in a store on each visit to the store,she may want to develop a confidence interval estimate.Suppose,she has determined the required sample size and feels that she cannot afford one that large.What options are available?

Accepted Answer

First,the formula for computing the samp

Question 19

In estimating a population proportion,the factors that are needed to determine the required sample size are the confidence level,the margin of error and some idea of what the population proportion is.

Accepted Answer

A) True 
 B)False

Question 20

A large Midwestern university is interested in estimating the mean time that students spend at the student recreation center per week.A previous study indicated that the standard deviation in time is about 40 minutes per week.If the officials wish to estimate the mean time within ± 10 minutes with a 90 percent confidence,what should the sample size be?

Accepted Answer

A) 44 
B) 62 
C) 302 
D) Can't be determined without knowing how many students there are at the university. 
A) 44 
B) 62 
C) 302 
D) Can't be determined without knowing how many students there are at the university.

When estimating sample size,a 90 percent confidence level will result in a smaller sample size than a 95 percent confidence level.

In an application to estimate the mean number of miles that downtown employees commute to work roundtrip each day,the following information is given: If the desired confidence level is 95 percent,the appropriate critical value is:

An emergency room in a hospital wants to determine the sample size needed for estimating their mean number of visits per day.If they want a 99 percent confidence level the correct critical value to use is 2.33.

What are the disadvantages of using a small sample to estimate the population mean?

If the population is not normally distributed,the t-distribution cannot be used.

If a decision maker desires a small margin of error and a high level of confidence,it is certain that the required sample size will be quite large.

A pilot sample is one that is used when a decision maker wishes to get an advance idea of what the mean of the population might be.

To find a 98 percent confidence interval where the standard deviation is known,the correct z-value to use for the critical value is 2.33.

If a manager believes that the required sample size is too large for a situation in which she desires to estimate the mean income of blue collar workers in a state,which of the following would lead to a reduction in sample size?

The main purpose of a pilot sample in an application involving an estimate for a population mean is to determine what the margin of error will likely be.

One way to reduce the margin of error in a confidence interval estimate is to lower the level of confidence.

If a manager is interested in estimating the mean time customers spend shopping in a store on each visit to the store,she may want to develop a confidence interval estimate.Suppose,she has determined the required sample size and feels that she cannot afford one that large.What options are available?

In estimating a population proportion,the factors that are needed to determine the required sample size are the confidence level,the margin of error and some idea of what the population proportion is.

The Where, why, and How of Data Collection

Graphs,charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Using Probability and Probability Distributions

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introduction to Quality and Statistical Process Control

Introduction to Decision Analysis

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Exam 8: Estimating Single Population Parameters

When estimating sample size,a 90 percent confidence level will result in a smaller sample size than a 95 percent confidence level.

In an application to estimate the mean number of miles that downtown employees commute to work roundtrip each day,the following information is given: If the desired confidence level is 95 percent,the appropriate critical value is:

An emergency room in a hospital wants to determine the sample size needed for estimating their mean number of visits per day.If they want a 99 percent confidence level the correct critical value to use is 2.33.

What are the disadvantages of using a small sample to estimate the population mean?

If the population is not normally distributed,the t-distribution cannot be used.

If a decision maker desires a small margin of error and a high level of confidence,it is certain that the required sample size will be quite large.

A pilot sample is one that is used when a decision maker wishes to get an advance idea of what the mean of the population might be.

To find a 98 percent confidence interval where the standard deviation is known,the correct z-value to use for the critical value is 2.33.

If a manager believes that the required sample size is too large for a situation in which she desires to estimate the mean income of blue collar workers in a state,which of the following would lead to a reduction in sample size?

The main purpose of a pilot sample in an application involving an estimate for a population mean is to determine what the margin of error will likely be.

One way to reduce the margin of error in a confidence interval estimate is to lower the level of confidence.

In estimating a population proportion,the factors that are needed to determine the required sample size are the confidence level,the margin of error and some idea of what the population proportion is.

The Where, why, and How of Data Collection

Graphs,charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Using Probability and Probability Distributions

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introduction to Quality and Statistical Process Control

Introduction to Decision Analysis

Filters