Question

Camp Jump Start is an 8-week summer camp for overweight and obese adolescents. counselors develop a weight-management program for each camper that centers on nutrition education and physical activity. To justify the cost of the camp, counselors must provide empirical evidence that the weight-management program is effective. Effectiveness is measured as the amount of weight lost (difference between before and after weights). In a study published in Pediatrics(April 2010), the BMI was measured for each of 76 campers both at the start and end of camp. Summary statistics on BMI measurements are shown below:

	Mean	St. Dev.
Starting BMI	34.9	6.9
Ending BMI	31.6	6.2
Paired Differences	3.3	1.5

1. Which hypothesis test should you use to see if the program is effective?

a. one-sample t test

b. paired t test

c. not enough information

1b. What are the null and alternative hypotheses?

a. H₀: µ_start = µ_end

H₁: µ_start < µ_end

_b. H₀: µ_d = 0

H₁: µ_d  > 0

c. H₀: µ_start = µ_end

H₁: µ_start < µ_end

1c. If the p-value is less than 0.001, what would you conclude?

a. The BMI change is significant

b. Might be a change, but need more information

Answer 1

1:

Since each camper is measured twice so it is paired data.

Correct option:

b. paired t test

2:

Conclusion:

a. The BMI change is significant