BUSINESS STATISTICS

1. In hypothesis testing, the null hypothesis should contain the equality sign

Select one:

True

False

2.The null and alternate hypotheses must be opposites of each other.

Select one:

True

False

3. A one-tailed hypothesis for a population mean with a significance level equal to .05 will have a critical value equal to z = .45.

Select one:

True

False

4. If a hypothesis test is conducted for a population mean, a null and alternative hypothesis of the form:

H0: = 100

H1: 100

will result in a one-tailed hypothesis test since the sample result can fall in only one tail.

Select one:

True

False

5.The following is an appropriate statement of the null and alternate hypotheses for a test of a population mean:

H0: < 50

H1: > 50

Select one:

True

False

6. A local medical center has advertised that the mean wait for services will be less than 15 minutes. Given this claim, the hypothesis test for the population mean should be a one-tailed test with the rejection region in the lower (left-hand) tail of the sampling distribution.

Select one:

True

False

7. A local medical center has advertised that the mean wait for services will be less than 15 minutes. Given this claim, the hypothesis test for the population mean should be a one-tailed test with the rejection region in the upper (right-hand) tail of the sampling distribution.

Select one:

True

False

8. A local medical center has advertised that the mean wait for services is 15 minutes. Given this claim, the hypothesis test for the population mean should be a two-tailed test with the rejection region in both (left and right-hand) tail of the sampling distribution.

Select one:

True

False

9.A large tire manufacturing company has claimed that its top line tire will average more than 80,000 miles. If a consumer group wished to test this claim, they would formulate the following null and alternative hypotheses:

H0: 80,000

H1: 80,000

Select one:

True

False

10.A large tire manufacturing company has claimed that its top line tire will average more than 80,000 miles. If a consumer group wished to test this claim, they would formulate the following null and alternative hypotheses:

H0:= 80,000

H1: 80,000

Select one:

True

False

11. A large tire manufacturing company has claimed that its top line tire will average more than 80,000 miles. If a consumer group wished to test this claim, they would formulate the following null and alternative hypotheses:

H0:80,000

H1:> 80,000

Select one:

True

False

12. A report recently published in a major business periodical stated that the average salary for female managers is less than $50,000. If we were interested in testing this, the following null and alternative hypotheses would be established:

H0: 50,000

H1: < 50,000

Select one:

True

False

13. A report recently published in a major business periodical stated that the average salary for female managers is less than $50,000. If we were interested in testing this, the following null and alternative hypotheses would be established:

H0:> 50,000

H1:< 50,000

Select one:

True

False

14. The police chief in a local city claims that the average speed for cars and trucks on a stretch of road near a school is at least 45 mph. If this claim is to be tested, the null and alternative hypotheses are:

H0: < 45 mph

H1: 45 mph

Select one:

True

False

15. The police chief in a local city claims that the average speed for cars and trucks on a stretch of road near a school is at least 45 mph. If this claim is to be tested, the null and alternative hypotheses are:

H0: 45 mph

H1: < 45 mph

Select one:

True

False

16. When a battery company claims that their batteries last longer than 100 hours and a consumer group wants to test this claim, the hypotheses should be:

H0: 100

H1: > 100

Select one:

True

False

17. The executive director of the United Way believes that more than 24 percent of the employees in the high-tech industry have made voluntary contributions to the United Way. In order to test this statistically, the appropriate null and alternative hypotheses are:

H0: p .24

H1: p > .24

Select one:

True

False

18. Which of the following would be an appropriate null hypothesis?

Select one:

a.

The mean of a population is greater than 55.

b.

The mean of a population is equal to 55.

c.

The mean of a sample is equal to 55.

d.

The mean of a sample is greater than 5

19. If an economist wishes to determine whether there is evidence that average family income in a community exceeds $25,000. The best null hypothesis is:

Select one:

a.

25,000.

b.

> 25,000.

c.

= 25,000.

d.

25,000.

20. A hypothesis test is to be conducted using an alpha = .05 level. This means:

Select one:

a.

there is a 5 percent chance that the alternative hypothesis is true.

b. there is a maximum 5 percent chance that a true null hypothesis will be rejected

c.

there is a 5 percent chance that the null hypothesis is true.

d.

there is a 5 percent chance that a Type II error has been committed

21. The reason for using the t-distribution in a hypothesis test about the population mean is:

Select one:

a.

the population standard deviation is unknown.

b.

the population is not normally distributed.

c.

it provides a smaller critical value than the standard normal distribution for a given sample size

22. A company that makes shampoo wants to test whether the average amount of shampoo per bottle is 16 ounces. The population standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.10 level of significance and a random sample of n = 64 bottles, which of the following would be the upper tail (right-tailed) critical value?

Select one:

a. z=2.575

b. z=1.645

c. z=1.28

d. z=1.96

23. A company that makes shampoo wants to test whether the average amount of shampoo per bottle is greater than 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.10 level of significance and a random sample of n = 64 bottles, which of the following would be the upper tail (right-tailed) critical value?

Select one:

a. z=1.96

b. z=1.645

c. z=1.285

d. z=2.575

24. A company that makes shampoo wants to test whether the average amount of shampoo per bottle is less than 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.025 level of significance and a random sample of n = 64 bottles, which of the following would be the left tail critical value?

Select one:

a. z= -2.575

b. z= -1.645

c. z= -1.285

d. z= -1.96

25. When testing a two-tailed hypothesis using a significance level of 0.05, a sample size of n = 16, and with the population standard deviation unknown, which of the following is true?

Select one:

a. The null hypothesis can be rejected if the sample mean gets too large or too small compared with the hypothesized mean

b.

All of the above are true.

c.

The test statistic will be a t-value.

d.

The alpha probability must be split in half and a rejection region must be formed on both sides of the sampling distribution.

26. When testing a two-tailed hypothesis using a significance level of 0.05, a sample size of n = 16, and with the population standard deviation unknown, what is/are the critical value(s)

Answer:

27. When testing a left-tailed hypothesis using a significance level of 0.05, a sample size of n = 7, and with the population standard deviation unknown, what is the critical value?

Answer:

28. When testing a right-tailed hypothesis using a significance level of 0.025, a sample size of n = 13, and with the population standard deviation unknown, what is the critical value?

Answer:

29. A house cleaning service claims that it can clean a four bedroom house in less than 2 hours. A sample of n = 16 houses is taken and the sample mean is found to be 1.97 hours and the sample standard deviation is found to be 0.1 hours. Write the null and alternate hypothesis.

Answer:

30. A house cleaning service claims that it can clean a four bedroom house in less than 2 hours. A sample of n = 16 houses is taken and the sample mean is found to be 1.97 hours and the sample standard deviation is found to be 0.1 hours. Significance level is 0.05.

Find the critical value.

Answer:

31. A house cleaning service claims that it can clean a four bedroom house in less than 2 hours. A sample of n = 16 houses is taken and the sample mean is found to be 1.97 hours and the sample standard deviation is found to be 0.1 hours. Significance level is 0.05.

Write the value of test statistic.

Answer:

32. A house cleaning service claims that it can clean a four bedroom house in less than 2 hours. A sample of n = 16 houses is taken and the sample mean is found to be 1.97 hours and the sample standard deviation is found to be 0.1 hours.

Write the decision to Reject H0 or Fail to Reject H0.

Answer:

33. A house cleaning service claims that it can clean a four bedroom house in less than 2 hours. A sample of n = 16 houses is taken and the sample mean is found to be 1.97 hours and the sample standard deviation is found to be 0.1 hours.

Write the interpretation base on the decision.

Answer:

34. Woof Chow Dog Food Company believes that it has a market share of 25 percent. It surveys n = 100 dog owners and ask whether or not Woof Chow is their regular brand of dog food. The appropriate null and alternate hypotheses are:

Select one:

a. H0: p 0.25 H1: p < 0.25

b. H0: p 0.25 H1: p > 0.25

c. H0: = 0.25 Ha: 0.25

d. H0: = 0.25 H1: 0.25

35. Woof Chow Dog Food Company believes that it has a market share of 25 percent. It surveys n = 100 dog owners and ask whether or not Woof Chow is their regular brand of dog food, and 23 people say yes. Based upon this information, what is the critical value if the hypothesis is to be tested at the 0.05 level of significance?

Select one:

a. z=1.645

b. z=2.575

c. z= 1.96

d. z= 1.285

36. Woof Chow Dog Food Company believes that it has a market share of 25 percent. It surveys n = 100 dog owners and ask whether or not Woof Chow is their regular brand of dog food, and 23 people say yes. Based upon this information, what is the value of the test statistic?

Select one:

a. Z statistic=0.475

b. Z statistic=0.462

c. Z statistic= -0.462

d. Z statistic= -0.475

37. Woof Chow Dog Food Company believes that it has a market share of 25 percent. It surveys n = 100 dog owners and ask whether or not Woof Chow is their regular brand of dog food, and 23 people say yes. Significance level is at 0.05. Based upon this information, what is the decision?

Select one:

a. Fail to Reject H1

b. Reject H0

c. Fail to reject H0

d. Reject H1

38. Woof Chow Dog Food Company believes that it has a market share of 25 percent. It surveys n = 100 dog owners and ask whether or not Woof Chow is their regular brand of dog food, and 23 people say yes. Significance level is at 0.05. Based upon this information, what is the interpretation?

Select one:

a. There is NOT enough evidence to Support the claim

b. There is enough evidence to Reject the claim

c. There is enough evidence to Support the claim

d. There is NOT enough evidence to Reject the claim

39. Write the steps in conducting hypothesis testing.

ANSWER:

40. A consumer group plans to test whether a new passenger car that is advertised to have a mean highway miles per gallon of at least 33 actually meets this level. They plan to test the hypothesis using a significance level of 0.05 and a sample size of n = 100 cars. It is believed that the population standard deviation is 3 mpg. Based upon this information, if the "true" population mean is 32.0 mpg, what is the test statistic?

Select one:

a. z statistic =0.0455

b. z statistic = 3..33

c. z statistic = 1.96

d. z statistic = -3..33