Question 1

In a lower tail hypothesis test situation, the p-value is determined to be .2.If the sample size for this test is 41, the t statistic has a value of

Accepted Answer

A)  .851. 
B)  -.851. 
C)  1.303. 
D)  -1.303. 
A)  .851. 
B)  -.851. 
C)  1.303. 
D)  -1.303.

Question 2

The sum of the values of α and β

Accepted Answer

A)  is always 1. 
B)  is always .5. 
C)  gives the probability of taking the correct decision. 
D)  is not needed in hypothesis testing. 
A)  is always 1. 
B)  is always .5. 
C)  gives the probability of taking the correct decision. 
D)  is not needed in hypothesis testing.

Question 3

You are given the following information obtained from a random sample of 5 observations.Assume the population has a normal distribution.   ​
You want to determine whether or not the mean of the population from which this sample was taken is significantly less than 21. 
a.
State the null and the alternative hypotheses.
b.
Compute the standard error of the mean.
c.
Determine the test statistic.
d.
Determine the p-value and at the 10% level of significance, test whether or not the mean of the population is significantly less than 21.

Accepted Answer

a. H₀: μ @#IMG-DLM& 21 H_a: μ < 21 b. .89

Question 4

​For a sample size of 30, changing from using the standard normal distribution to using the t distribution in a hypothesis test,

Accepted Answer

A)  ​will result in the area corresponding to the critical value being larger. 
B)  ​will result in the area corresponding to the critical value being smaller. 
C)  ​will have no effect on the area corresponding to the critical value. 
D)  ​Not enough information is given to answer this question. 
A)  ​will result in the area corresponding to the critical value being larger. 
B)  ​will result in the area corresponding to the critical value being smaller. 
C)  ​will have no effect on the area corresponding to the critical value. 
D)  ​Not enough information is given to answer this question.

Question 5

For a two-tailed hypothesis test with a sample size of 32 and a .10 level of significance, the critical values of the test statistic t are

Accepted Answer

A)  -1.699 and 1.699. 
B)  -1.311 and 1.311. 
C)  -1.310 and 1.310 . 
D)  -1.697 and 1.697. 
A)  -1.699 and 1.699. 
B)  -1.311 and 1.311. 
C)  -1.310 and 1.310 . 
D)  -1.697 and 1.697.

Question 6

At a local university, a sample of 49 evening students was selected in order to determine whether the average age of the students is significantly different from 21 years.The average age of the students in the sample was 23 years with a standard deviation of 3.5 years.
a.
Formulate the hypotheses for this problem.
b.
Compute the test statistic.
c.
Determine the p-value and test these hypotheses.Let α = .05.

Accepted Answer

a. H₀: μ = 21 years

Question 7

A Type II error is committed when

Accepted Answer

A)  a true alternative hypothesis is mistakenly rejected. 
B)  a true null hypothesis is mistakenly rejected. 
C)  the true null hypothesis is correctly rejected. 
D)  the true alternative hypothesis is correctly rejected. 
A)  a true alternative hypothesis is mistakenly rejected. 
B)  a true null hypothesis is mistakenly rejected. 
C)  the true null hypothesis is correctly rejected. 
D)  the true alternative hypothesis is correctly rejected.

Question 8

Read the z statistic from the normal distribution table and choose the correct answer.For a one-tailed test (upper tail) at α = .0630, z =

Accepted Answer

A)  -1.53. 
B)  0.335. 
C)  -0.335. 
D)  1.53. 
A)  -1.53. 
B)  0.335. 
C)  -0.335. 
D)  1.53.

Question 9

A grocery store has an average sales of $8000 per day.The store introduced several advertising campaigns in order to increase sales.To determine whether or not the advertising campaigns have been effective in increasing sales, a sample of 100 days of sales was selected.It was found that the average was $8200 per day.From past information, it is known that the standard deviation of the population is $1500.The correct null hypothesis for this problem is

Accepted Answer

A)  μ  8200. 
A)  μ  8200.

Question 10

Nancy believes that the average running time of movies is equal to 140 minutes.A sample of 4 movies was taken and the following running times (in minutes) were obtained.Assume the population of the running times is normally distributed.   ​ 
a.
Compute the sample mean and the standard deviation.
b.
State the null and alternative hypotheses.
c.
Using the critical value approach, test the hypotheses at the 10% level of significance.
d.
Using the p-value approach, test the hypotheses at the 10% level of significance.

Accepted Answer

​
a. @#IMG-DLM& = 162.5 minutes; s = 15

Question 11

For a two-tailed hypothesis test about ?, we can use any of the following approaches except

Accepted Answer

A)  compare the confidence interval estimate of   to the hypothesized value of ?. 
B)  compare the p-value to the value of ?. 
C)  compare the value of the test statistic to the critical value. 
D)  compare the level of significance to the confidence coefficient. 
A)  compare the confidence interval estimate of   to the hypothesized value of ?. 
B)  compare the p-value to the value of ?. 
C)  compare the value of the test statistic to the critical value. 
D)  compare the level of significance to the confidence coefficient.

Question 12

The p-value is

Accepted Answer

A)  the same as the z statistic. 
B)  a sample statistic. 
C)  a distance. 
D)  a probability. 
A)  the same as the z statistic. 
B)  a sample statistic. 
C)  a distance. 
D)  a probability.

Question 13

In a two-tailed hypothesis test, the test statistic is determined to be z = 2.5.The p-value for this test is

Accepted Answer

A)  .9876. 
B)  .4938. 
C)  .0062. 
D)  .0124. 
A)  .9876. 
B)  .4938. 
C)  .0062. 
D)  .0124.

Question 14

A random sample of 100 people was taken.Eighty of the people in the sample favored Candidate A.We are interested in determining whether the proportion of the population in favor of Candidate A is significantly more than 75%.The test statistic is

Accepted Answer

A)  .8. 
B)  .75. 
C)  1.15. 
D)  -1.25. 
A)  .8. 
B)  .75. 
C)  1.15. 
D)  -1.25.

Question 15

If the probability of a Type I error (α) is .05, then the probability of a Type II error (β) must be

Accepted Answer

A)  .05. 
B)  .95. 
C)  .025. 
D)  Cannot be computed. 
A)  .05. 
B)  .95. 
C)  .025. 
D)  Cannot be computed.

Question 16

Last year, 50% of MNM, Inc., employees were female.It is believed that there has been a reduction in the percentage of females in the company.This year, in a random sample of 400 employees, 180 were female.
a.
Give the null and the alternative hypotheses.
b.
b.
At the .05 level using the critical value approach, determine if there has been a significant reduction in the proportion of females.
c.
Show that the p-value approach results in the same conclusion as that of part

Accepted Answer

a. H₀: p ≥ .5 H_a: p < .5 b. Te

Question 17

A two-tailed test is performed at the .05 level of significance.The p-value is determined to be .01.The null hypothesis

Accepted Answer

A)  must be rejected. 
B)  should not be rejected. 
C)  could be rejected, depending on the sample size. 
D)  has been designed incorrectly. 
A)  must be rejected. 
B)  should not be rejected. 
C)  could be rejected, depending on the sample size. 
D)  has been designed incorrectly.

Question 18

For the following hypothesis test, H0: μ ≥ 150
Ha: μ < 150
​
The test statistic

Accepted Answer

A)  must be negative. 
B)  must be positive. 
C)  can be either negative or positive. 
D)  must be a number between zero and one. 
A)  must be negative. 
B)  must be positive. 
C)  can be either negative or positive. 
D)  must be a number between zero and one.

Question 19

A student believes that the average grade on the statistics final examination was 87.A sample of 36 past final examinations was taken.The average grade in the sample was 83.96 with a standard deviation of 12.
a.
State the null and alternative hypotheses.
b.
Using the critical value approach, test the hypotheses at the 5% level of significance.
c.
Using the p-value approach, test the hypotheses at the 5% level of significance.

Accepted Answer

a. H₀: μ = 87 H_a: μ ≠ 87 b. te

Question 20

When the p-value is used for hypothesis testing, the null hypothesis is rejected if

Accepted Answer

A)  p-value  $\lt$ ?. 
B)  ?  $\lt$ p-value. 
C)  p-value=1-  $\lt$?/2. 
D)  p-value =1- $\alpha$ 
A)  p-value  $\lt$ ?. 
B)  ?  $\lt$ p-value. 
C)  p-value=1-  $\lt$?/2. 
D)  p-value =1- $\alpha$

In a lower tail hypothesis test situation, the p-value is determined to be .2.If the sample size for this test is 41, the t statistic has a value of

The sum of the values of α and β

For a sample size of 30, changing from using the standard normal distribution to using the t distribution in a hypothesis test,

For a two-tailed hypothesis test with a sample size of 32 and a .10 level of significance, the critical values of the test statistic t are

A Type II error is committed when

Read the z statistic from the normal distribution table and choose the correct answer.For a one-tailed test (upper tail) at α = .0630, z =

For a two-tailed hypothesis test about ?, we can use any of the following approaches except

The p-value is

In a two-tailed hypothesis test, the test statistic is determined to be z = 2.5.The p-value for this test is

A random sample of 100 people was taken.Eighty of the people in the sample favored Candidate A.We are interested in determining whether the proportion of the population in favor of Candidate A is significantly more than 75%.The test statistic is

If the probability of a Type I error (α) is .05, then the probability of a Type II error (β) must be

A two-tailed test is performed at the .05 level of significance.The p-value is determined to be .01.The null hypothesis

For the following hypothesis test, H₀: μ ≥ 150 H_a: μ < 150 The test statistic

When the p-value is used for hypothesis testing, the null hypothesis is rejected if

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Tests of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Filters

Exam 9: Hypothesis Tests

In a lower tail hypothesis test situation, the p-value is determined to be .2.If the sample size for this test is 41, the t statistic has a value of

The sum of the values of α and β

​For a sample size of 30, changing from using the standard normal distribution to using the t distribution in a hypothesis test,

For a two-tailed hypothesis test with a sample size of 32 and a .10 level of significance, the critical values of the test statistic t are

A Type II error is committed when

Read the z statistic from the normal distribution table and choose the correct answer.For a one-tailed test (upper tail) at α = .0630, z =

For a two-tailed hypothesis test about ?, we can use any of the following approaches except

The p-value is

In a two-tailed hypothesis test, the test statistic is determined to be z = 2.5.The p-value for this test is

A random sample of 100 people was taken.Eighty of the people in the sample favored Candidate A.We are interested in determining whether the proportion of the population in favor of Candidate A is significantly more than 75%.The test statistic is

If the probability of a Type I error (α) is .05, then the probability of a Type II error (β) must be

A two-tailed test is performed at the .05 level of significance.The p-value is determined to be .01.The null hypothesis

For the following hypothesis test, H0: μ ≥ 150 Ha: μ < 150 ​ The test statistic

When the p-value is used for hypothesis testing, the null hypothesis is rejected if

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Tests of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Filters

For a sample size of 30, changing from using the standard normal distribution to using the t distribution in a hypothesis test,

For the following hypothesis test, H₀: μ ≥ 150 H_a: μ < 150 The test statistic