It is given in the question that
A farmer owns about 960 acres of land. If his farm is square.
First we convert acres to miles square, and the conversion expression is

Therefore,

Let the side length of the square be x miles .
And the formula of area of square is

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)
Answer:
The answer of this question is (D) 8
(5,7),(2,1)
slope = (1 - 7) / (2 - 5) = -6/-3 = 2 <==