Could you please assist me with this question?

thanks in advance,

7. Twenty-four 9th- and 10th-grade high school girls were put on ultraheavy rope- jumping program. The following data give the time difference in seconds for each girl (" before program time" minus "after program time" ) for the 40-yard dash: 0.28 0.01 0.13 0.33 -0.03 0.07 -0.18 -0.14 -0.33 0.01 0.22 0.29 -0.08 0.23 0.08 0.04 -0.30 -0.08 0.09 0.70 0.33 -0.34 0.50 0.06 (a) Give a point estimate of up, the mean of the difference in race times. (b) Find a one-sided approximate 95% confidence interval that is a lower bound for up. (c) Does it look like rope-jumping program was effective