So far I have this and the answer is -1 + square root symbol 7 over 2 but I don't know if I am doing this right

answer: city needs 2.4 inches of rainfall more to match the record of 40 inches.

step-by-step explanation:

since we have given that

total annual rainfall a city record = 40 inches

this year, total rainfall recorded = 37.6 inches

number of inches of rainfall   is needed to match the record of 40 inches is given by

hence, city needs 2.4 inches of rainfall more to match the record of 40 inches.

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify