Chapter 11 Review - AP Statistics

Which of the following best describes a Type I error?

• The null is true, but we mistakenly reject it.

• The null is false and we reject it.

• The null is false, but we fail to reject it.

• The null is true but we fail to reject it.

• The null is true, and we fail to reject it.

When p-value is greater than alpha we:

• Accept Ho
• Accept Ha
• Fail to reject Ho
• Reject Ho

What is the Power of a test?

• A strong force
• The probability that we correctly reject a false null.
• The probability that we correctly accept a true null.
• How tough it is.

Which of the following best describes a type II error?

• The null is true, but we mistakenly reject it.

• The null is false and we reject it.

• The null is false, but we fail to reject it.

• The null is true but we fail to reject it.

• Te null is false, and we reject it.

What does it mean when a test is statistically significant?

• it has reached alpha level status
• the test statistic had a P-value higher than the alpha level
• the test statistic had a P-value lower than the alpha level
• it is important in practical terms

A P-value indicates:

• the probability that the null hypothesis is true

• the probability that the alternative hypothesis is true

• the probability of obtaining the observed results (or one more extreme) if the null hypothesis is true

• probability of a Type I error

At the Chrysler manufacturing plant, there is a part that is supposed to weigh 19 pounds, on average. The engineers take a sample of parts and want to know if they meet the weight specifications. Their sample's mean weight is 17 pounds What are our null and alternative hypotheses?

• H_o : μ = 17

  H_a : μ ≠ 19

• H_o : μ = 19

  H_a : μ ≠ 19

• H_o : μ = 19

  H_a : μ ≠ 17

• H_o : μ = 17

  H_a : μ ≠ 17

Which of the following represents the appropriate null & alternative hypotheses?

"We want to show that the mean height of women is greater than 64"

• H₀: μ = 64"

  Hₐ: μ ≠ 64"

• H₀: μ = 64"

  Hₐ: μ > 64"

• H₀: p = 64"

  Hₐ: p ≠ 64"

• H₀: p = 64"

  Hₐ: p > 64"

The probability of observing a value for a test statistic at least as far from the hypothesized value as the statistic value actually observed if the null hypothesis is true

• P-Hat
• One-Proportion z-test
• Z*
• P-Value

Suppose the P-value for a hypothesis test is 0.0304. Using a = 0.05, what is the appropriate conclusion?

• a) reject the null, the probability of getting results like this given the null is true is 3.04% which is less than 5%.

• b) reject the alternative, the probability of getting results like this given the alternative is true is 3.04% which is less than 5%.

• c) Accept the null, a 3.04% chance is really not that bad.

• d) Fail to reject the alternative but still don't accept the null.