5/2=2 1/2 + 2/5 = 2.9 = 2 9/10
The <em><u>correct answer</u></em> is:
c)75.4 to 94.6
Explanation:
The formula for a confidence interval is:
,
where μ is the mean, z is the z-score associated with the level of confidence we want, σ is the standard deviation, and n is the sample size.
Our mean is 85, our standard deviation is 12, our sample size is 6, and since we want 95% confidence, our z-score is 1.96:

Px + qy = r
2px - qy = 2r
----------------add
3px = 3r
x = 3r/3p
x = r/p
It’s 8^6, you’re correct :)