Question 1

The ____________________ confidence limit of the confidence interval estimator of the population variance is   .

Accepted Answer

The answer of The ____________________ confidence limit of the confidence...

Question 2

Mystic Pizza: Mystic Pizza in Mystic, Connecticut, advertises that they deliver your pizza within 15 minutes of placing an order or it is free. A sample of 25 customers is selected at random. The average delivery time in the sample was 13 minutes with a sample standard deviation of 4 minutes.
-What is the required condition of the technique used in the previous question?

Accepted Answer

Delivery t

Question 3

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively.
-Test the hypothesis H0: $\mu$ = 125 vs. H1: $\mu$$\neq$125 at the 10% significance level.

Accepted Answer

Rejection region: | t | > t_0.05,99<

Question 4

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42. If the 10% level of significance were used in testing the hypotheses H0: $\mu$ = 201 vs. H1: $\mu$ $\neq$201, the null hypothesis:

Accepted Answer

A)  would be rejected. 
B)  would be accepted. 
C)  would fail to be rejected. 
D)  would become H0: $\mu$$\neq$201 
A)  would be rejected. 
B)  would be accepted. 
C)  would fail to be rejected. 
D)  would become H0: $\mu$$\neq$201

Question 5

The t-distribution allows the calculation of confidence intervals for means for small samples when the population variance is not known, regardless of the shape of the distribution in the population.

Accepted Answer

A) True 
 B)False

Question 6

A pharmaceutical company has just developed a new capsule to alleviate the symptoms of allergies and colds. However, they are concerned about the variability in the amount of time until the drug becomes effective. In a random sample of 10 individuals who suffer from allergies, the amount of time (in hours) for the capsule to take effect was recorded and listed as follows: 5, 7, 6, 10, 9, 12, 8, 17, 4, and 16. Estimate with 90% confidence the variance of the time for the drug to become effective.

Accepted Answer

@#IMG-DLM& We estimate that the variance

Question 7

Hourly Fees: A random sample of 15 hourly fees for car washers (including tips) was drawn from a normal population. The sample mean and sample standard deviation were   = $14.9 and s = $6.75.
-Can we infer at the 5% significance level that the population mean is greater than 12, assuming that you know the population standard deviation is equal to 6.75?

Accepted Answer

Rejection region: z > z_0.05 = 1.64

Question 8

The area to the right of a certain critical value on a chi-squared distribution is 0.025. For 5 degrees of freedom, the critical value is 11.143.

Accepted Answer

A) True 
 B)False

Question 9

Researchers determined that 60 Puffs tissues is the average number of tissues used during a cold. Suppose a random sample of 100 Puffs users yielded the following data on the number of tissues used during a cold:   = 52 and s = 22. Suppose the alternative we wanted to test was H1: $\mu$ < 60. The correct rejection region for $\alpha$ = 0.05 is:

Accepted Answer

A) reject H0 if t > 1.6604. B) reject H0 if t 0 if t > 1.9842 or Z 0 if t < -1.9842. A) reject H0 if t > 1.6604. B) reject H0 if t 0 if t > 1.9842 or Z 0 if t < -1.9842.

Question 10

For a 99% confidence interval of the population mean based on a sample of n = 25 with s = 0.05, the critical value of t is:

Accepted Answer

A)  2.7969 
B)  2.7874 
C)  2.4922 
D)  2.4851 
A)  2.7969 
B)  2.7874 
C)  2.4922 
D)  2.4851

Question 11

____________________ populations allow us to use the confidence interval estimate of a mean to produce a confidence interval estimate of the population total.

Accepted Answer

The answer of ____________________ populations allow us to use the...

Question 12

The t-distribution assumes that the population is normally distributed.

Accepted Answer

A) True 
 B)False

Question 13

Mystic Pizza: Mystic Pizza in Mystic, Connecticut, advertises that they deliver your pizza within 15 minutes of placing an order or it is free. A sample of 25 customers is selected at random. The average delivery time in the sample was 13 minutes with a sample standard deviation of 4 minutes.
-We want to know whether Mystic can make this claim or not. Test to determine if we can infer at the 5% significance level that the population mean delivery time is less than 15 minutes.

Accepted Answer

H₀: @#LAT-DLM& = 15, H₁: @#LAT-DLM&< 1

Question 14

The t-distribution is used to develop a confidence interval estimate of the population mean when the population standard deviation is unknown.

Accepted Answer

A) True 
 B)False

Question 15

If we are testing for an improvement in the consistency of an operation or the manufacturing of a product, the alternative hypothesis would have a(n) ____________________ sign in it.

Accepted Answer

The answer of If we are testing for an improvement...

Question 16

The chi-squared test and estimator of the population variance ____________________(are/are not) valid if the population is slightly to moderately nonnormal.

Accepted Answer

The answer of The chi-squared test and estimator of the...

Question 17

The t-distribution is used in a confidence interval for a mean when the actual standard error is not known.

Accepted Answer

A) True 
 B)False

Question 18

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively.
-Explain how to use the confidence interval to test the hypotheses at$\alpha$= 0.10.

Accepted Answer

Since the hypothesized value @#LAT-DLM&<

Question 19

If a sample has 18 observations and a 90% confidence estimate for $\mu$ is needed, the appropriate value of t is 1.740.

Accepted Answer

A) True 
 B)False

Question 20

An investor is concerned with the risk associated with a portfolio of stocks. He draws a random sample of nine monthly returns (expressed as a percentage of the initial investment). These data follow: 2, 5, -6, 10, 1, 2, -3, 0, and 7. Find a 95% confidence interval estimate of the population variance.

Accepted Answer

LCL = 10.9

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively. -Test the hypothesis H₀: $\mu$ = 125 vs. H₁: $\mu$ $\neq$ 125 at the 10% significance level.

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42. If the 10% level of significance were used in testing the hypotheses H₀: $\mu$ = 201 vs. H₁: $\mu$ $\neq$ 201, the null hypothesis:

The t-distribution allows the calculation of confidence intervals for means for small samples when the population variance is not known, regardless of the shape of the distribution in the population.

The area to the right of a certain critical value on a chi-squared distribution is 0.025. For 5 degrees of freedom, the critical value is 11.143.

For a 99% confidence interval of the population mean based on a sample of n = 25 with s = 0.05, the critical value of t is:

____________________ populations allow us to use the confidence interval estimate of a mean to produce a confidence interval estimate of the population total.

The t-distribution assumes that the population is normally distributed.

The t-distribution is used to develop a confidence interval estimate of the population mean when the population standard deviation is unknown.

If we are testing for an improvement in the consistency of an operation or the manufacturing of a product, the alternative hypothesis would have a(n) ____________________ sign in it.

The chi-squared test and estimator of the population variance ____________________(are/are not) valid if the population is slightly to moderately nonnormal.

The t-distribution is used in a confidence interval for a mean when the actual standard error is not known.

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively. -Explain how to use the confidence interval to test the hypotheses at $\alpha$ = 0.10.

If a sample has 18 observations and a 90% confidence estimate for $\mu$ is needed, the appropriate value of t is 1.740.

What Is Statistics

Graphical and Tabular Descriptive Techniques

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About Comparing Two Populations, Part 1

Inference About Comparing Two Populations, Part 2

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Review of Statistical Inference

Filters

Exam 11: Inference About a Population

The ____________________ confidence limit of the confidence interval estimator of the population variance is .

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively. -Test the hypothesis H0: μ\muμ = 125 vs. H1: μ\muμ≠\neq= 125 at the 10% significance level.

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42. If the 10% level of significance were used in testing the hypotheses H0: μ\muμ = 201 vs. H1: μ\muμ ≠\neq= 201, the null hypothesis:

The t-distribution allows the calculation of confidence intervals for means for small samples when the population variance is not known, regardless of the shape of the distribution in the population.

The area to the right of a certain critical value on a chi-squared distribution is 0.025. For 5 degrees of freedom, the critical value is 11.143.

For a 99% confidence interval of the population mean based on a sample of n = 25 with s = 0.05, the critical value of t is:

____________________ populations allow us to use the confidence interval estimate of a mean to produce a confidence interval estimate of the population total.

The t-distribution assumes that the population is normally distributed.

The t-distribution is used to develop a confidence interval estimate of the population mean when the population standard deviation is unknown.

If we are testing for an improvement in the consistency of an operation or the manufacturing of a product, the alternative hypothesis would have a(n) ____________________ sign in it.

The chi-squared test and estimator of the population variance ____________________(are/are not) valid if the population is slightly to moderately nonnormal.

The t-distribution is used in a confidence interval for a mean when the actual standard error is not known.

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively. -Explain how to use the confidence interval to test the hypotheses at α\alphaα = 0.10.

If a sample has 18 observations and a 90% confidence estimate for μ\muμ is needed, the appropriate value of t is 1.740.

What Is Statistics

Graphical and Tabular Descriptive Techniques

Numerical Descriptive Techniques

Data Collection and Sampling

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About Comparing Two Populations, Part 1

Inference About Comparing Two Populations, Part 2

Analysis of Variance

Chi-Squared Tests

Simple Linear Regression and Correlation

Multiple Regression

Review of Statistical Inference

Filters

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively. -Test the hypothesis H₀: $\mu$ = 125 vs. H₁: $\mu$ $\neq$ 125 at the 10% significance level.

Based on sample data, the 90% confidence interval limits for the population mean are LCL = 170.86 and UCL = 195.42. If the 10% level of significance were used in testing the hypotheses H₀: $\mu$ = 201 vs. H₁: $\mu$ $\neq$ 201, the null hypothesis:

Concert Tickets: A simple random sample of 100 concert tickets was drawn from a normal population. The mean and standard deviation of the sample were $120 and $25, respectively. -Explain how to use the confidence interval to test the hypotheses at $\alpha$ = 0.10.

If a sample has 18 observations and a 90% confidence estimate for $\mu$ is needed, the appropriate value of t is 1.740.