I believe the answer is D. 18
Given that the mean is $9.5 and the standard deviation is $1.30, the standard error will be given by:
σ/√n
where
σ-standard deviation
n=sample size
thus, we shal have:
1.30/√20
=0.2906
Next we find the margin error
0.2906*2=0.581
thus the confidence interval will be:
(9.5+0.581, 9.5-0.581)
=(10.081,8.919)
(square root of x)^2 < (5)^2
x<25
The answer is about 36.9%
I just guessed and checked. 95-60= 35
So .3685×95 is the closest to equaling 35
