Question

The amount of money spent weekly on cleaning, maintenance, and repairs at a large restaurant was observed over a long period of time to be approximately normally distributed, with mean μ = $597 and standard deviation σ = $39.

(a) If $646 is budgeted for next week, what is the probability that the actual costs will exceed the budgeted amount?

Answer 1

z = ( X - Mean ) / SD
z = ( 646 - 597 ) / 39
z = 49/39 = 1.25
With the z-score table:
for z = 1.25, p = 0.8944 ( probability that the cost will be lower than $646 )
1 - 0.8944 = 0.1056
Answer: The probability is 0.1056