1. [Excel Question] The number of days building a new detached home follow a normal distribution with mean of 300 days and standard deviation of 25 days. If it exceeds 350 days, a late completion penalty will occur. Answer the following questions using Excel.

(a) What percent of new detached homes is built in less than 290 days? Hint: use the Excel function NORM.DIST(x, mean, std dev, true)

(b) Find Q1 and Q3. Hint: use the Excel function NORM.INV(probability, mean, std dev)

(c) What is the probability incurring a penalty? Hint: Use the complement event and the Excel function NORM.DIST