Question

Question 15 (1 point)

It is believed that students who begin studying for final exams a week before the test score differently than students who wait until the night before. Suppose you want to test the hypothesis that students who study one week before score greater than students who study the night before. A hypothesis test for two independent samples is run based on your data and a p-value is calculated to be 0.0428. What is the appropriate conclusion?

Question 15 options:

	1) The average score of students who study one week before a test is significantly different from the average score of students who wait to study until the night before a test.
	2) We did not find enough evidence to say the average score of students who study one week before a test is greater than the average score of students who wait to study until the night before a test.
	3) The average score of students who study one week before a test is less than or equal to the average score of students who wait to study until the night before a test.
	4) The average score of students who study one week before a test is significantly less than the average score of students who wait to study until the night before a test.
	5) The average score of students who study one week before a test is significantly greater than the average score of students who wait to study until the night before a test.

Question 16 (1 point)

You are looking for a way to incentivize the sales reps that you are in charge of. You design an incentive plan as a way to help increase in their sales. To evaluate this innovative plan, you take a random sample of your reps, and their weekly incomes before and after the plan were recorded. You calculate the difference in income as (after incentive plan - before incentive plan). You perform a paired samples t-test with the following hypotheses: Null Hypothesis: μ_D ≥ 0, Alternative Hypothesis: μ_D < 0. You calculate a p-value of 0.0542. What is the appropriate conclusion of your test?

Question 16 options:

	1) The average difference in weekly income is greater than or equal to 0.
	2) We did not find enough evidence to say there was a significantly negative average difference in weekly income. The incentive plan does not appear to have been effective.
	3) The average difference in weekly income is significantly less than 0. The average weekly income was higher before the incentive plan.
	4) We did not find enough evidence to say the average difference in weekly income was not 0. The incentive plan does not appear to have been effective.
	5) We did not find enough evidence to say there was a significantly positive average difference in weekly income. The incentive plan does not appear to have been effective.

Question 17 (1 point)

It is reported in USA Today that the average flight cost nationwide is $325.69. You have never paid close to that amount and you want to perform a hypothesis test that the true average is actually less than $325.69. The hypotheses for this situation are as follows: Null Hypothesis: μ ≥ 325.69, Alternative Hypothesis: μ < 325.69. If the true average flight cost nationwide is $300.92 and the null hypothesis is not rejected, did a type I, type II, or no error occur?

Question 17 options:

	1) Type II Error has occurred.
	2) Type I Error has occurred
	3) We do not know the degrees of freedom, so we cannot determine if an error has occurred.
	4) No error has occurred.
	5) We do not know the p-value, so we cannot determine if an error has occurred.

Answer 1

Ans 15.

H₀ :students who study one week before score equal to the students who study the night before.

H₁ :students who study one week before score greater than students who study the night before

Here we assume level of significance= 5% i.e Alpha=0.05

P value=0.0428  

Since, P value=0.0428 < Alpha=0.05

Hence we reject the null hypothesis.

Hence, The average score of students who study one week before a test is significantly different from the average score of students who wait to study until the night before a test.

Option (1) is true.

Ans 16

H₀ : μ_D ≥ 0

H₁ : μ_D < 0

Here we assume level of significance= 5% i.e Alpha=0.05 P value= 0.0542

Since, P value=0.0542 > Alpha=0.05

Hence , we accept the null hypothesis.

Hence, The average difference in weekly income is greater than or equal to 0.

Option (1) is true.

Ans 17

H₀ :μ ≥ $325.69

H₁ : μ < $325.69

If the true average flight cost nationwide is $300.92 (<325.69) and the null hypothesis is not rejected (H₀ accepted)

Accepting H₀ when H₁ is true = Type II Error

Hence, Option (1) is true.