AP Statistics Writing Hypotheses

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

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

The weight of the average 6th grade student's backpack (with books in it) is 18.4 lbs. The principal of the school thinks that the backpack does not weight 18.4 lbs. What is the null and alternate hypothesis?

• H₀ = 18.4
  H_a = 18.4

• H₀ = 18.4
  H_a > 18.4

• H₀ = 18.4
  H_a < 18.4

• H₀ = 18.4
  H_a ≠ 18.4

• A

• B

• C

• D

• E

Which of the following is the FIRST step of a hypothesis test?

• Check assumptions & conditions

• Find your test statistic

• State your conclusion

• State your null & alternative hypotheses

A test is made of H₀ : µ = 17 versus H₁ : µ < 17 is performed using α = 0.01 significance level. The value of the test statistic is z = -2.68 and it is concluded that H₀ is rejected.

If the true value of µ is 17, is the conclusion a Type I Error, Type II error, or a correct decision?

• Type I

• Type II

• Correct Decision

A test is made of H₀ : µ = 50 versus H₁ : µ =/= 50 is performed using α = 0.01 significance level. The value of the test statistic is z = -2.68 and it is concluded that we fail to reject H₀ .

If the true value of µ is 65, is the conclusion a Type I Error, Type II error, or a correct decision?

• Type I

• Type II

• Correct Decision

A test is made of H₀ : µ = 50 versus H₁ : µ =/= 50 is performed using α = 0.01 significance level. The value of the test statistic is z = -2.68 and it is concluded that we fail to reject H₀ .

If the true value of µ is 50, is the conclusion a Type I Error, Type II error, or a correct decision?

• Type I

• Type II

• Correct Decision

A car manufacturer advertises that its new subcompact models get 47 mpg. If μ is the mileage of these cars, what could be the null and alternate hypothesis if we wanted to check if the car's mpg is overrated?

• H₀ = 47
  H_a = 47

• H₀ = 47
  H_a < 47

• H₀ = 47
  H_a > 47

• H₀ = 47
  H_a ≠ 47

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