Question 1

Increasing the sample size n will result in a point estimate that is closer to the true value of the population parameter.

Accepted Answer

A) True 
 B)False  False

Question 2

The type of sample statistic that is used to make inferences about a given type of population parameter is called:

Accepted Answer

A)  the estimator of that parameter 
B)  the confidence level of that parameter 
C)  the confidence interval of that parameter 
D)  the point estimate of that parameter 
E)  the interval estimate of that parameter 
A)  the estimator of that parameter 
B)  the confidence level of that parameter 
C)  the confidence interval of that parameter 
D)  the point estimate of that parameter 
E)  the interval estimate of that parameter A

Question 3

If the campaign manager of John Kerry is interested in estimating the proportion of registered voters who will support Kerry on November 2nd, 2004, the sample proportion   would be the appropriate point estimate.

Accepted Answer

A) True 
 B)False  True

Question 4

A researcher wants to determine the proportion of elm trees in Superior, Wisconsin, dying of Dutch elm disease. Past experiments based on large sample sizes have shown this proportion to be 0.3. What sample size does the researcher need in order to estimate this proportion to within 0.04 with 95% confidence?
______________

Accepted Answer

The answer of A researcher wants to determine the proportion...

Question 5

An estimator is a random variable calculated from a random sample that provides either a point estimate or an interval estimate for some population parameter.

Accepted Answer

A) True 
 B)False

Question 6

The term confidence interval refers to the range of values among which an unknown population parameter can presumably be found.

Accepted Answer

A) True 
 B)False

Question 7

A study conducted by a commuter train transportation authority involved surveying a random sample of 200 passengers. The results show that a customer had to wait on the average 9.3 minutes with a standard deviation of 6.2 minutes to buy his or her ticket. Construct a 95% confidence interval for   , the true mean waiting time.
______________

Accepted Answer

The answer of A study conducted by a commuter train...

Question 8

A childcare agency was interested in examining the amount that families pay per child per month for childcare outside the home. A random sample of 64 families was selected and the mean and standard deviation were computed to be $675 and $80, respectively.
Find a 95% confidence interval for the true average amount spent per child per month for childcare outside the home.
______________
Interpret the interval.
________________________________________________________
A social worker claims that the average amount spent per child per month outside the home is $700. Based on the interval above, can this claim be rejected?
______________
Justify your answer.
________________________________________________________

Accepted Answer

(655.4, 694.6); One can estimate with 95

Question 9

When estimating a population mean μ , where the population standard deviation σ is known, we can:

Accepted Answer

A)  define the limits of an interval estimate of μ as   
B)  define the limits of an interval estimate of μ as   
C)  choose a smaller z value, construct a narrower confidence interval, and achieve a higher confidence level 
D)  choose a larger z value, construct a wider confidence interval, and achieve a lower confidence level 
A)  define the limits of an interval estimate of μ as   
B)  define the limits of an interval estimate of μ as   
C)  choose a smaller z value, construct a narrower confidence interval, and achieve a higher confidence level 
D)  choose a larger z value, construct a wider confidence interval, and achieve a lower confidence level

Question 10

A random sample of 400 Michigan State University (MSU) students were surveyed recently to determine an estimate for the proportion of all MSU students who had attended at least three football games. The estimate revealed that between .372 and .458 of all MSU students attended. Given this information, we can determine that the confidence coefficient was approximately:

Accepted Answer

A)  .99 
B)  .95 
C)  .92 
D)  .90 
E)  .88 
A)  .99 
B)  .95 
C)  .92 
D)  .90 
E)  .88

Question 11

Suppose you wish to estimate a population proportion p based on sample of n observations. What sample size is required if you want your estimate to be within .03 of p with probability equal to 0.90?

Accepted Answer

A)  752 
B)  423 
C)  1,068 
D)  1.529 
E)  none of these 
A)  752 
B)  423 
C)  1,068 
D)  1.529 
E)  none of these

Question 12

The lower and upper limits of the 68.26% confidence interval for the population mean   , given that n = 49;   = 75; and   = 7, are 74 and 76, respectively.

Accepted Answer

A) True 
 B)False

Question 13

A 90% confidence interval estimate of the population mean   can be interpreted to mean that:

Accepted Answer

A)  if we repeatedly draw samples of the same size from the same population, 90% of the values of the sample meanswill result in a confidence interval that includes the population mean. 
B)  there is a 90% probability that the population meanwill lie between the lower confidence limit (LCL) and the upper confidence limit (UCL). 
C)  we are 90% confident that we have selected a sample whose range of values does not contain the population mean. 
D)  we are 90% confident that 10% the values of the sample meanswill result in a confidence interval that includes the population mean. 
E)  90% of the values of the sample meansare equal to the population mean. 
A)  if we repeatedly draw samples of the same size from the same population, 90% of the values of the sample meanswill result in a confidence interval that includes the population mean. 
B)  there is a 90% probability that the population meanwill lie between the lower confidence limit (LCL) and the upper confidence limit (UCL). 
C)  we are 90% confident that we have selected a sample whose range of values does not contain the population mean. 
D)  we are 90% confident that 10% the values of the sample meanswill result in a confidence interval that includes the population mean. 
E)  90% of the values of the sample meansare equal to the population mean.

Question 14

In developing an interval estimate for a population mean, a sample of 40 observations was used. The interval estimate was 17.25   2.42. Had the sample size been 160 instead of 40, the interval estimate would have been:

Accepted Answer

A)  17.259.68 
B)  17.251.21 
C)  69.009.68 
D)  34.504.82 
E)  69.001.21 
A)  17.259.68 
B)  17.251.21 
C)  69.009.68 
D)  34.504.82 
E)  69.001.21

Question 15

Whenever a sampled population is normally distributed or whenever the conditions of the central limit theorem are fulfilled, the sample mean,   :

Accepted Answer

A)  is a consistent estimator of the population mean,, because the mean of the sampling distribution of the sample mean, equals 
B)  is an efficient estimator of the population mean,, because the mean of the sampling distribution of the sample mean equals 
C)  is an unbiased estimator of the population mean,, because the mean of the sampling distribution of the sample mean equals 
D)  is a biased estimator of the population mean,, because the mean of the sampling distribution of the sample proportion equals p 
E)  is an efficient estimator of the population mean,, because the mean of the sampling distribution of the sample proportion equals p 
A)  is a consistent estimator of the population mean,, because the mean of the sampling distribution of the sample mean, equals 
B)  is an efficient estimator of the population mean,, because the mean of the sampling distribution of the sample mean equals 
C)  is an unbiased estimator of the population mean,, because the mean of the sampling distribution of the sample mean equals 
D)  is a biased estimator of the population mean,, because the mean of the sampling distribution of the sample proportion equals p 
E)  is an efficient estimator of the population mean,, because the mean of the sampling distribution of the sample proportion equals p

Question 16

Suppose a 90% confidence interval for the mean time it takes to serve a customer at a drive-in bank is 120 seconds to 220 seconds. In repeated sampling 90% of the intervals constructed using the appropriate formula will contain the actual mean time.

Accepted Answer

A) True 
 B)False

Question 17

Radio and television stations often air controversial issues during broadcast time and ask viewers to indicate their agreement or disagreement with a given stand on the issue. A poll is conducted by asking those viewers who agree to call a certain 900 telephone number and those who disagree to call a second 900 telephone number. All respondents pay a fee for their calls.
Does this polling technique result in a random sample?
______________
Are the results of such a survey valid?
______________
Explain.
________________________________________________________

Accepted Answer

No; No; This method of sampling would no

Question 18

If we wish to construct a 95% confidence interval estimate for the difference between two population proportions, then the confidence level would be:

Accepted Answer

A)  1.96 
B)  0.475 
C)  0.95 
D)  0.05 
E)  2.33 
A)  1.96 
B)  0.475 
C)  0.95 
D)  0.05 
E)  2.33

Question 19

A manufacturer wishes to estimate the mean time a battery pack will function before needing to be recharged with a margin of error of no more than 0.5 hours and with probability 0.95. If the standard deviation is known to be 1.5 hours, how many observations should be included in the sample?
______________

Accepted Answer

The answer of A manufacturer wishes to estimate the mean...

Question 20

An auto mechanic knows the average time it takes to replace a bad car radiator is 70 minutes with a standard deviation of 12 minutes. This average is based on a random sample of 50. Construct a 90% confidence interval for   .
______________

Accepted Answer

The answer of An auto mechanic knows the average time...

Increasing the sample size n will result in a point estimate that is closer to the true value of the population parameter.

The type of sample statistic that is used to make inferences about a given type of population parameter is called:

If the campaign manager of John Kerry is interested in estimating the proportion of registered voters who will support Kerry on November 2^nd, 2004, the sample proportion would be the appropriate point estimate.

An estimator is a random variable calculated from a random sample that provides either a point estimate or an interval estimate for some population parameter.

The term confidence interval refers to the range of values among which an unknown population parameter can presumably be found.

When estimating a population mean μ , where the population standard deviation σ is known, we can:

Suppose you wish to estimate a population proportion p based on sample of n observations. What sample size is required if you want your estimate to be within .03 of p with probability equal to 0.90?

The lower and upper limits of the 68.26% confidence interval for the population mean , given that n = 49; = 75; and = 7, are 74 and 76, respectively.

A 90% confidence interval estimate of the population mean can be interpreted to mean that:

In developing an interval estimate for a population mean, a sample of 40 observations was used. The interval estimate was 17.25 2.42. Had the sample size been 160 instead of 40, the interval estimate would have been:

Whenever a sampled population is normally distributed or whenever the conditions of the central limit theorem are fulfilled, the sample mean, :

Suppose a 90% confidence interval for the mean time it takes to serve a customer at a drive-in bank is 120 seconds to 220 seconds. In repeated sampling 90% of the intervals constructed using the appropriate formula will contain the actual mean time.

If we wish to construct a 95% confidence interval estimate for the difference between two population proportions, then the confidence level would be:

An auto mechanic knows the average time it takes to replace a bad car radiator is 70 minutes with a standard deviation of 12 minutes. This average is based on a random sample of 50. Construct a 90% confidence interval for . ______________

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

Probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

Large-Sample Tests of Hypotheses

Inference From Small Samples

The Analysis of Variance

Linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

Nonparametric Statistics

Filters

Exam 8: Large-Sample Estimation

Increasing the sample size n will result in a point estimate that is closer to the true value of the population parameter.

The type of sample statistic that is used to make inferences about a given type of population parameter is called:

If the campaign manager of John Kerry is interested in estimating the proportion of registered voters who will support Kerry on November 2nd, 2004, the sample proportion would be the appropriate point estimate.

An estimator is a random variable calculated from a random sample that provides either a point estimate or an interval estimate for some population parameter.

The term confidence interval refers to the range of values among which an unknown population parameter can presumably be found.

When estimating a population mean μ , where the population standard deviation σ is known, we can:

Suppose you wish to estimate a population proportion p based on sample of n observations. What sample size is required if you want your estimate to be within .03 of p with probability equal to 0.90?

The lower and upper limits of the 68.26% confidence interval for the population mean , given that n = 49; = 75; and = 7, are 74 and 76, respectively.

A 90% confidence interval estimate of the population mean can be interpreted to mean that:

In developing an interval estimate for a population mean, a sample of 40 observations was used. The interval estimate was 17.25 2.42. Had the sample size been 160 instead of 40, the interval estimate would have been:

Whenever a sampled population is normally distributed or whenever the conditions of the central limit theorem are fulfilled, the sample mean, :

Suppose a 90% confidence interval for the mean time it takes to serve a customer at a drive-in bank is 120 seconds to 220 seconds. In repeated sampling 90% of the intervals constructed using the appropriate formula will contain the actual mean time.

If we wish to construct a 95% confidence interval estimate for the difference between two population proportions, then the confidence level would be:

An auto mechanic knows the average time it takes to replace a bad car radiator is 70 minutes with a standard deviation of 12 minutes. This average is based on a random sample of 50. Construct a 90% confidence interval for . ______________

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

Probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

Large-Sample Tests of Hypotheses

Inference From Small Samples

The Analysis of Variance

Linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

Nonparametric Statistics

Filters

If the campaign manager of John Kerry is interested in estimating the proportion of registered voters who will support Kerry on November 2^nd, 2004, the sample proportion would be the appropriate point estimate.