1. A luxury furniture manufacture will make custom furniture for their customers. Pricing is based on the number of hours of skilled labor it takes to make a piece. The time it takes to make a custom couch is normally distributedwith an average of 280 hours and a standard deviation of 40 hours.

a. What percent of custom couches take between 240 to 320 hours to make?

b. What percent of custom couches take 255 hours or less to make?

c. How long would it take to build a couch that is in the 95th percentile?