Question

Pick the best choice

A researcher examined if a new prep-course has an effect on the final exammm scores among BCX students. He selected 20 BCX students and ask them to complete the prep-course for three weeks before the final exammm. After analyzing the sample data, the one-sample t-statistics was 2.08. With α = .05, the two-tailed test, what can he conclude?

*Failed to reject the null hypothesis and conclude that the new-prep course has no effect.
*Reject the null hypothesis and conclude that the prep-course had an effect.
*Reject the null hypothesis and conclude that the new-prep course has no effect.
*Failed to reject the null hypothesis and conclude that the new-prep course has an effect.

A researcher compared a sample of XDS students (n = 8) and a sample of XDS students (n = 10) on the GPA. After computing the difference between the two groups, he found t= 1.75.

-Reject the null hypothesis, and there is no difference between two groups on the GPA.
-Failed to reject the null hypothesis, and there is no difference between two groups on the GPA.
-Reject the null hypothesis, and there is a difference between two groups on the GPA.
-Failed to reject the null hypothesis, and there is a difference between two groups on the GPA.

Which of the following research situations would be most likely to use an independent-measures design?
*Examine the long-term effectiveness of a stop-smoking treatment by interviewing subjects 2 months and 6 months after the treatment ends.
*Compare the blood-pressure readings before medication and after medication for a group a patients with high blood pressure.
*Compare the mathematics skills for 9th-grade boys versus 9th-grade girls.
*Examine the development of vocabulary as a group of children mature from age 2 to age 3.

Which of the following research situations is most likely to use an independent design?
*Evaluate the effectiveness of a pain reliever by measuring how much pain is reduced after taking the medication.
*Evaluate the difference in self-esteem between student athletes and non-athletes
*Evaluate the developmental change of verbal skills as a sample of 30 girls matures from age 2 to age    3.
*Evaluate the effectiveness of a cholesterol medication by comparing cholesterol levels before and after the medication.

When n is small (less than 30), how does the shape of the t distribution compare to the normal distribution?

-It is perfectly normal.
-It is flatter and more spread out than the normal distribution.
-It is taller and narrower than the normal distribution.
-None of the options

Answer 1

Answer 1.Failed to reject the null hypothesis and conclude that the new-prep course has no effect.

H₀: There is no effect

H_A: There is significant effect

The p-value is .051303 > significance level.

Answer 2. Failed to reject the null hypothesis, and there is no difference between two groups on the GPA.

H₀: There is no difference between the two groups

H_A: There is a difference between the two groups

DOF: min (n₁-1, n₂-1) = min ((8-1), (10-1)) = 7

Then P (T <= 1.75) = 0.9382 or P (T < 1.75) = 0.0618 + 0.0618 =0.1236

Here, P-value (0.0618) is greater than the significance level of 0.05. We fail to reject the null hypothesis.

Answer 3. Compare the mathematics skills for 9th-grade boys versus 9th-grade girls. As two groups are involved here.

Answer 4. Evaluate the difference in self-esteem between student-athletes and non-athletes. As two groups are

involved here

Answer 5. It is flatter and more spread out than the normal distribution.