compute an interval estimate with 90% confidence for the mean time to complete an employment test. Assuming a population standard deviation of three hours, what is the required sample size if the error should be less than a half hour

The required sample size 'n' = 97 .41 hours

Step-by-step explanation:

Explanation:-

Given standard deviation of the Population 'σ' = 3 hours

Given the Margin of error =

The Margin of error is determined by

Given level of significance ∝ = 0.10 or 0.90

Z₀.₁₀ = 1.645

Cross multiplication , we get

√n =  9.87

Squaring on both sides, we get

n = 97.41 hours

Final -

The required sample size 'n' = 97.41 hours

$4034.40

the perimeter of the field is the sum of the lengths of the four sides:

47 yd + 158 yd + 47 yd + 158 yd = 410 yd

the cost of 3 ft (1 yd) of fence is 3×$3.28 = $9.84.

so the cost of jake's wood perimeter fance is

(410 yd) × ($9.84 /yd) = $4034.40