Question

For each problem, select the correct response.

(a) What is the P-value of a test of the null hypothesis?

A. The probability the null hypothesis is false

B. The probability, assuming the null hypothesis is false, that the test statistic will take a value at least as extreme as that actually observed

C. The probability the null hypothesis is true

D. The probability, assuming the null hypothesis is true, that the test statistic will take a value at least as extreme as that actually observed

(b) You plan to construct a confidence interval for the mean μ of a Normal population with (known) standard deviation σ. Which of the following actions will reduce the size of the margin of error?

A. Use a lower level of confidence.

B. Reduce σ.

C. Increase the sample size.

D. All of these options are correct.

(c) You collect a random sample of size n from a population; from the data collected, you compute a 95% confidence interval for the mean of the population. Which of the following would produce a new confidence interval with larger width (larger margin of error) based on these same data?

A. Use the same confidence level but compute the interval n times. Approximately 5% of these intervals will be larger.

B. Use a smaller confidence level.

C. Use a larger confidence level.

D. Nothing can guarantee absolutely that you will get a larger interval. We can say only that the chance of obtaining a larger interval is 0.05.

(d) Which of the following is NOT an assumption included in the simple conditions for inference about a mean?

A. A population mean that is known

B. Response variable with a perfect Normal distribution in the population

C. Simple random sampling with no nonresponse or other practical difficulty

D. A population standard deviation that is known

(e) (1 MARK) When performing a test of hypotheses, when does a Type I error occur?

A. When we incorrectly accept the alternative hypothesis

B. When we incorrectly reject the alternative hypothesis

C. When we incorrectly reject the null hypothesis

D. When we incorrectly accept the null hypothesis

Answer 1

a)

D. The probability, assuming the null hypothesis is true, that the test statistic will take a value at least as extreme as that actually observed

b)D. All of these options are correct.

c)

C. Use a larger confidence level.

d)

D. A population standard deviation that is known

e)

C. When we incorrectly reject the null hypothesis