A newly graduated public health student starts an intervention to increase the amount of exercise in a south San Jose community. He enrolls 20 participants, and measures their mean daily exercise duration before the program and after the program.

	sample size (n)	mean (minutes)	standard deviation
Before program	20	15.75
After program	20	34.03
Delta (D)	20	18.28 (xd)	23.55

For this study, is there a significant increase in exercise after the program? To answer this question, conduct a statistical test. What type of sample is this?

Group of answer choices

One-sample

Paired

Independent

Select the null and alternative hypotheses.

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_D = 0 and _D > 0

_D = 0 and _D # 0

_D = 0 and _D < 0

₁ = ₂ and ₁ # ₂

Is this a 1-tailed or 2-tailed test?

Group of answer choices

1-tailed

2-tailed

Calculate the Standard Error:

Group of answer choices

5.269

5.352

5.266

5.260

How many degrees of freedom are there?

Group of answer choices

19

18

20

21

Calculate the test statistic:

Group of answer choices

3.47

4.09

3.49

1.18

This corresponds to a final p-value of:

Group of answer choices

0.0025 < p < 0.001

0.005 < p < 0.002

0.05 < p < 0.02

0.005 < p < 0.0025

Based on the p-value and the -value, do you conclude that you should reject or not reject the null hypothesis?

Group of answer choices

Reject

Not reject

Thus we summarize that:

Group of answer choices

There isa significant increase in exercise as a result of the program.

There is NOT a significant increase in exercise as a result of the program.