Question

Every year students at a high school take a physical fitness test during their gym classes. One component of the test asks them to do as many​ push-ups as they can. Results for one class are shown​ below, according to gender. Assuming that students are assigned to gym classes at​ random, create a​ 90% confidence interval for how many more​ push-ups boys can do than​ girls, on​ average, at that high school.

Boys   Girls
18   23
29   6
32   15
18   16
27   2
33   15
30   19
22   26
23   10
18   27
13   32
33   9

The confidence interval is ( _ , _ ).

​(Round to one decimal place as​ needed.)

Answer 1

standard error se =Sp*√(1/n1+1/n2)=

3.300

point estimate of difference=x1-x2=	8.000
for 90 % CI & 22 df value of t=		1.717
margin of error E=t*std error =	5.6658
lower bound=mean difference-E=	2.3342
Upper bound=mean differnce +E=	13.6658
from above 90% confidence interval for population mean =(2.3 , 13.7)

(please try 2.1 ,13.9 if above comes wrong and reply)