24 girls in the 9th and 10th grades were put on an ultra-heavy rope-jumping program. Someone thought that such a program would increase their speed in the 40-yard dash. let D equal the difference in time to run the 40-yard dash - the 'before-program time' minus the "after-program time". Assume that the distribution of D is approximately N(μD, σ²D).

The following data give the difference in time that it took each girl to run the 40-yard dash, with positive numbers indicating a faster time after the program:
0.2 0.01 0.18 0.34 -0.04 0.05
-0.16 -0.16 -0.32 0.02 0.2 0.2
-0.1 0.2 0 0.03 -0.1 -0.06
0.01 0.8 0.37 -0.39 0.7 0.03

Find the following and then calculate a 90% confidence interval for D: