Question

How much should be budgeted for weekly repairs, cleaning, and maintenance so that the probability that the budgeted amount will be exceeded in a given week is only 0.13

Answer 1

$425.6 is the amount that needs to be budgeted

Explanation:

P(Y >y)=0.1 3

P( (Y − µ )/σ > (y − 400 )/20 )=0.1 3

P(Z >( y − 400 )/20 )=0.1 3

(y − 400 )/20 ≈ 1.28

y ≈ (1.28)(20) + 400

y ≈ 425.60