Question:

Answer: C. The test provides convincing evidence that the proportion is greater than 90%, but the actual proportion is equal to 90%.

Question: At a manufacturing company, the percent of defective items produced on the assembly line is 2%. The company is testing a new assembly line designed to reduce the percent of defective parts. The null and alternative hypotheses of the test are described as follows.

Answer: C. The test does not provide convincing evidence that the percent is less than 2%, but the actual percent is 1%.

Question: Which of the following is defined by the significance level of a hypothesis test?

Answer: D. The probability of Type I error

Question: Consider a hypothesis test in which the significance level is α=0.05 and the probability of a Type II error is 0.18. What is the power of the test

Answer: B. 0.82

Question: If all other factors are held constant, which of the following results in an increase in the probability of a Type II error?

Answer: C. The significance level is decreased.

Question: If all other factors are held constant, which of the following results in a decrease in the probability of a Type II error?

Answer: D. The standard error is decreased.

Question: A new drug to treat a certain condition is being tested. The null hypothesis of the test is that the drug is not effective. For the researchers, the more consequential error would be for the drug to be effective, but the test does not detect the effect.

Answer: A. Increase the significance level to increase the probability of Type I error.

Question:

Answer: D. Decrease the significance level to decrease the probability of Type I error.

Question:

Answer: E. A two-sample z-interval for a difference in population proportions

Question: Which of the following indicates that the use of a two-sample z-interval for a difference in population proportions is appropriate?

Answer: D. I and II only.