X=19 X =8. X = 8.35

N=17 N =40 N= 30

S=5 s=1.6 s=1.59

What is the Confidence interval at 95%

a)
Given that:

x 19, s 5 and n 17

The 95% of confidence interval is,

Hence, the required 95% of confidence interval is:

b)
Given that:

16.429 21.571

x 8, s 1.6 and n 40

The 95% of…