1. An airline claims that 90% of lost luggage is recovered and delivered to its owner within 24 hours. A researcher is skeptical of this claim and believes this percentage is too high. She writes her null hypothesis as being "p > 0.90." What is wrong with this?

Choose the correct answer

A. Nothing is wrong.

B. The null hypothesis should be p < 0.90.

C. The null hypothesis should be p = 0.90.

D. The null hypothesis should be two-sided.

E. We cannot determine what might be wrong without knowing more details about the sample size and the sample proportion.

2. Which one of the following statements is correct?

Choose the correct answer

A. When conducting a hypothesis test, the claim being tested about the population is called an alternative hypothesis.

B. We always begin a hypothesis test by assuming that the null hypothesis is true.

C. The test statistic will be positive if the sample proportion is smaller than the claimed population proportion.

D. The test statistic is not affected by the size of the sample

. E. A large P-value means we have strong evidence against the null hypothesis.

3. According to a recent report, 71% of high school seniors have a driver's license. A school administrator is skeptical of this claim. He surveys a random sample of 424 high school seniors and finds that 318 of them have a driver's license. Based on this information, what will the test statistic be? Choose the answer below that is closest to what you calculate, and try not to do a lot of rounding until you get to the very end of your calculations.

Choose the correct answer

A. Smaller than 1.0 B. 1.8 C. 2.4 D. 1.2 E. Larger than 3.0

4. Is red your favorite color? It's claimed that in the population, the proportion of adults who favor the color red is 0.25. You believe the true population proportion is smaller than 0.25. After surveying a large random sample of adults and conducting a hypothesis test, you obtain a test statistic of -2.1. Based on this information, which one of the following statements is correct?

Choose the correct answer

A. The value of 0.25 is a statistic.

B. If a hypothesis test is conducted at significance level of 0.05, we should conclude that the results of the test are statistically significant.

C. If a hypothesis test is conducted, the P-value will be smaller than 0.01.

D. Although not given in the problem, we can determine, based on the value of the test statistic, that the sample proportion must have been 0.229.

E. The alternative hypothesis in this case would be two-sided.

5. A report claims that 19.6% of high school students use e-cigarettes. A public health official believes a different percentage of high school students use e-cigarettes. This official surveys a random sample of 1,000 high school students about their e-cigarette use in order to conduct a hypothesis test. If this hypothesis test yields a test statistic of -1.8, what can we conclude about the P-value?

Choose the correct answer

A. The P-value will be smaller than 0.01.

B. The P-value will be between 0.01 and 0.05.

C. The P-value will be between 0.05 and 0.10.

D. The P-value will be larger than 0.10.

E. It's impossible to know what the P-value will be without knowing the sample proportion.

6. A claim is made that 14% of credit card users make only the minimum payment toward their credit card debt each month. A financial institution believes this claim is incorrect. They would like to test the null hypothesis that = 0.14 versus the alternative hypothesis that 0.14. Upon gathering data from a large random sample of credit card users, they obtain a value of z equal to 2.4. If the significance (or alpha) level is 0.01, what would be the appropriate conclusion?

Choose the correct answer

A. A conclusion cannot be reached without knowing the exact sample size.

B. The null hypothesis is true.

C. The null hypothesis is false.

D. The null hypothesis should be rejected.

E. The null hypothesis should not be rejected.

7. Although it is reported that the proportion of college students who regularly pull "all-nighters" is 0.20, there is some dispute about this claim, with the belief being that the true population proportion is actually less than 0.20. Suppose data is gathered from a large random sample of college students in order to conduct a hypothesis test, and the resulting P-value is 0.04. Which one of the following is a correct interpretation of this P-value?

Choose the correct answer

A. The probability of obtaining a sample result as extreme or more extreme than the one observed, under the assumption that the null hypothesis is true, is 0.04.

B. There is a 4% chance that if we randomly select one college student from the population of all college students, that one student will regularly pull "all-nighters."

C. Because the P-value is small, we cannot rule out the null hypothesis as a reasonable explanation of the data.

D. The probability that the null hypothesis is false is 0.04.

E. The probability that the null hypothesis is true is 0.04.

8. In lecture, we talked about the difference between statistical significance and practical significance. If we say the results of a hypothesis test are practically significant, what does this mean?

Choose the correct answer

A. The results would be unlikely to occur just by chance alone, if we assume the null hypothesis is true.

B. The P-value must have been very small.

C. The results have important real world implications.

D. The null hypothesis was rejected.

E. All of the above answers are correct.

9. A hypothesis test is conducted in which the null hypothesis is p = 0.37 and the alternative is p > 0.37. Data is gathered from a random sample and a test statistic of 1.3 is computed. This means our P-value would have to be

Choose the correct answer

A. larger than 0.10.

B. between 0.05 and 0.10.

C. between 0.01 and 0.05.

D. smaller than 0.01.

E. More information is needed in order to determine the P-value.

10. Which one of the following statements is false?

Choose the correct answer

A. When conducting a two-sided test, the test statistic needs to be multiplied by two.

B. We do not need to know the significance level in order to compute a P-value.

C. The "P" in P-value is stands for "probability."

D. A P-value can never be negative.

E. The population proportion is a parameter.