I dont' really understand this question.

Question

The construction industry has determined that the average time to construct a two floor, family house in Westchester County, New York takes 85 days -- with a deviation of 10 days. Mr. Cox wants to purchase a new home in Westchester County, but his builder has just instructed him that his houses may take 106 days. Mr. Cox's bankers/lenders will guarantee him $400k if his Z-score(based upon a 106 day completion) is normal. (that's the hint) Does Mr. Cox receive the money? Explain.

Could anyone help me out with this please? I'm not sure how to answer this question.

average mean (mu aka, mean from which score X was obtained) = 85
sigma (standard deviation of normal distribution from which X was obtained) = 10
estimated mean (X aka, raw score) = 106

z(obs) = (X - mu)/sigma

z(obs) = (106 - 85)/10

z(obs) = 2.1

check +2.1 in z-score table (which should be in the back of your book) to see if percentile is normal. :) good luck

Thanks!