Hypothesis Testing Questions and Answers

The t table is used when the population standard deviation is known and the z tables is used when the population standard deviation is not known.

True

False

If alpha is .05 what is the significance level (input as a decimal with two significant digits e.g. .14 instead of 14% or 14)?

Please refer to the following to answer the questions below.

The owner of Limp Pines Resort wants to know if the average age of its clients has changed in the past decade. Prior research (10 years ago) showed that the population mean was 53 years old with a population standard deviation of 9 years.  A random sample of 70 clients is taken. It shows a mean age of 48 years. Perform a hypothesis test at a .1 significance level to see whether there is enough evidence to say that the mean age of clients has changed?

Which of the following is the alternative hypothesis?

a. µ ≠ 53

b. µ = 53

c. µ < 53

d. µ > 53

In this case is it appropriate to calculate a z or t value?

a. z

b. t

Is this a one sided or two sided test? And, therefore, what is the z critical value to look up?

a. Two sided, zalpha/2

b. One sided, zalpha

c. One sided, zalpha/2

d. Two sided, zalpha

What is the value of the appropriately calculated z or t value (the value calculated using the appropriate z or t formula, not the critical value from the table; input as a number with two significant digits e.g. 3.14)?

What is the appropriate z or t critical value (obtained from the table or by using excel)?

a. .05

b. 1.96

c. .95

d. 1.645

What is the appropriate conclusion from this test?

a. Reject the null, at a 10% significance level we conclude that the mean age has not changed in the past decade.

b. Do not reject the null, at a 10% significance level we conclude that the mean age has changed in the past decade.

c. Do not reject the null, at a 10% significance level we conclude that the mean age has not changed in the past decade.

d. Reject the null, at a 10% significance level we conclude that the mean age has changed in the past decade.

What is the alternative hypothesis?

a. p ≠ .45

b. p = .45

c. p > .45

d. p < .45

Would you use a t or z critical value to perform a hypothesis test?

a. t

b. z

Which of the following can you conclude from the test?

a. At a .05% significance, we can not reject the null and say that the test worked.  Therefore, we should stop reminding people about the items.

b. At a .05% significance, we can reject the null and say that the test worked.  Therefore, we should continue reminding people about the items.

c. At a .1% significance, we can not reject the null and say that the test worked.  Therefore, we should stop reminding people about the items.

d. At a .1% significance, we can reject the null and say that the test worked.  Therefore, we should continue reminding people about the items.