Question

2. Using the same information as question one, compute a 99% confidence interval for the mean difference. Based on the interval, make a statistical decision about the null hypothesis and briefly state why you came to your conclusion.

1. Professional sports teams use the vertical jump to gauge the strength of athletes. This test requires a person to stand flat footed and leap vertically into the air and touch the highest

reachable mark. A typical person in the population can jump 28 inches. That is, the population average is 28 inches. An athletic trainer recruited a group of 15 college athletes and had them perform the vertical jump test. She wanted to know if these college athletes would be different than a typical person in the population. Athletes in her sample had an average score of 32.3 inches and a standard deviation of 6.5 inches.

a. State the null and alternative hypothesis.

b. Conduct a hypothesis test using a significance level of 0.05.

c. Compute a 95% confidence interval for the

mean difference

d. Compute Cohen’s d effect size.

e. Interpret the results. (Make sure that you include all of the necessary statistics:

means (or mean difference), t, p, 95% CI, and effect size.)

Answer 1