A family of four averages 85 loads of laundry per month.One such family does 62 loads per month and has a z-score of -2.3.Find the standard deviation.
A)20 loads
B)10 loads
C)1 load
D)2 loads
E)3 loads

Question

Quizplus · Accepted Answer

We can use the formula for z-score:
z = (x - μ) / σ

where
z = -2.3
x = 62 loads
μ = 85 loads (mean)
σ = standard deviation

Solving for σ, we get:

σ = (x - μ) / z
σ = (62 - 85) / (-2.3)
σ ≈ 10

Therefore, the standard deviation is approximately 10 loads per month. So the best choice is B.

A Family of Four Averages 85 Loads of Laundry Per