Question 1

Which of the following best describes the null hypothesis ($$H_0) in $$hypothesis testing?

Accepted Answer

A statement that is assumed true until evidence indicates otherwise.

Question 2

A researcher wants to test if the mean amount of time spent working on weekends by employed male Americans is greater than 5.46 hours. Which is the correct set of hypotheses?

Accepted Answer

$$H_0$$: \mu = 5.46$$; H_1$: \mu \u003e 5.46$$

Question 3

What is a Type I error in hypothesis testing?

Accepted Answer

Rejecting the null hypothesis when it is true.

Question 4

If the probability of making a Type I error is $$\alpha = 0.05$$, what does this mean?

Accepted Answer

There is a 5% chance of rejecting the null hypothesis when it is true.

Question 5

A sample of 120 registered voters finds 44 are Republicans. If the population proportion is $$p_0 = 0.42$, what is the sample proportion $$\hat{p}$$?

Accepted Answer

$$\hat{p} = \frac{44}{120} = 0.37$$

Question 6

Which formula gives the standard deviation of the sampling distribution of $$\hat{p}$$?

Accepted Answer

$$\sigma_{\hat{p}} = \sqrt{\frac{p(1-p)}{n}}$$

Question 7

In the P-value approach, what is the correct decision if $$P-$$value $$\u003c \alpha$$?

Accepted Answer

Reject the null hypothesis.

Question 8

A fast-food manager tests if the mean bill per car has increased from $$\mu_0$ = 13.20. A $$sample of 35 cars has $$\bar{x} = 13.96$$ and $$s = 3.69. $$Which test statistic should be used?

Accepted Answer

$$t_0$$ = \frac{\bar{x} - \$$mu_0$$}{s / \sqrt{n}}$$

Question 9

Which of the following is true about the chi-square distribution?

Accepted Answer

It is not symmetric and becomes more symmetric as degrees of freedom increase.

Question 10

A quality control engineer tests if the standard deviation of fill volumes is greater than 0.05 liters. Which hypotheses should be used?

Accepted Answer

$$H_0$$: \sigma = 0.05$$; H_1$: \sigma \u003e 0.05$$

Question 11

If a 95% confidence interval for a proportion contains the value stated in the null hypothesis, what is the correct conclusion?

Accepted Answer

Do not reject the null hypothesis.

Question 12

Which formula is used to test hypotheses about a population standard deviation using the chi-square distribution?

Accepted Answer

$$\$$chi^2$$ = \frac{(n-1)s^2$}{\$$sigma^2$$}$$

Question 13

Which of the following best describes practical significance?

Accepted Answer

A result that is statistically significant but may not be important in real life.

Question 14

If $$np(1-p) \u003c 10$$, which method should be used to test hypotheses about a population proportion?

Accepted Answer

Binomial probability distribution.

Question 15

A marketing manager wants to test if the proportion of seniors who prefer name brand coffee differs from 55%. Which type of test is appropriate?

Accepted Answer

Two-tailed test.

Question 16

Which of the following is the correct formula for the test statistic in a hypothesis test for a population mean (large sample)?

Accepted Answer

$$t_0$$ = \frac{\bar{x} - \$$mu_0$$}{s / \sqrt{n}}$$

Question 17

Which of the following is NOT a requirement for using the normal model to test hypotheses about a population proportion?

Accepted Answer

The sample size must be less than 5.

Question 18

If the P-value is 0.003, what is the strength of evidence against the null hypothesis?

Accepted Answer

Strong evidence against the null hypothesis.

Question 19

Which parameter is addressed in a hypothesis test using the formula $$\$$chi^2$$ = \frac{(n-1)s^2$}{\$$sigma^2$$}$$?

Accepted Answer

Population standard deviation $$\sigma$$

Chapter 10: Hypothesis Testing: Concepts, Errors, and Methods

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