Hypothesis Testing Statistics Introduction

A level of significance of 5% means:

• There's a 5% chance we're wrong

• There's a 5% chance we'll be wrong if we fail to reject the null hypothesis

• There's a 5% chance we'll be wrong if we reject the null hypothesis.

• There's a 5% chance you'll get an A on the test.

In performing a hypothesis test where the null hypothesis is that the μ = 6.9. A random sample of 16 items is selected. The sample mean is 7.1 and the sample standard deviation is 2.4. It can be assumed that the population is normally distributed at α = .05.

• Reject Ho

• Reject Ha

• Fail to reject Ho

• Fail to reject Ha

A fast food outlet claims that the mean waiting time in

line is less than 1.9 minutes. A random sample of 20

customers has a mean of 1.7 minutes with a standard

deviation of 0.8 minute. If α = 0.05, test the fast food

outlet's claim using P-values.

• Reject Ho

• Reject Ha

• Fail to reject Ho

• Fail to reject Ha

A fast food outlet claims that the mean waiting time in

line is less than 3.5 minutes. A random sample of 20

customers has a mean of 3.7 minutes with a standard

deviation of 0.8 minute. If α = 0.05, test the fast food

outlet's claim.

• Reject Ho

• Reject Ha

• Fail to reject Ho

• Fail to reject Ha

If a sample mean is in the critical region with alpha level 0.01, it would still(always) be in the critical region if alpha were changed to 0.05?

• False

• True

A mayor is concerned about the percentage of city residents who express disapproval of his job performance. His political committee pays for a newspaper ad, hoping to keep his disapproval rating below 21%. They will use a follow up poll to access effectiveness. What are the correct null and alternative hypotheses?

• Ho: μ > 21

  Ha: μ < 21

• Ho: p > .20

  Ha: p < .20

• Ho: p < .21

  Ha: p > .21

• Ho: p > .21

  Ha: p < .21

At the Chrysler manufacturing plant, there is a part that is supposed to weigh precisely 19 pounds. The engineers take a sample of parts and want to know if they meet the weight specifications. 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

Use the notation to state the alternative hypothesis and null hypothesis: "Less than 4% of high school students take Statistics."

• H_o : X ≥ 4% and H₁ : X > 4%

• H_o : X ≤ 4% and H₁ : X < 4%

• H_o : X ≥ 4% and H₁ : X < 4%

• H_o : X > 4% and H₁ : X ≤ 4%

When do you use a t-value instead of a z-value?

• When n < 30

• When n ≥ 30

• When all of the planets align

• When the teacher says so