The bicycle shop in Exercise 55 estimates using current labor costs that unpacking a bike costs $0.82 on average with a standard deviation of $0.16. Assembly costs $8.00 on average with a standard deviation of $0.88 and tuning costs $4.10 with a standard deviation of $0.90. Because the costs are directly related to the times, you can use the same assumptions as in exercise 55.
a) Define your random variables, and use them to express the total cost of the bike set up.
b) Find the mean set up cost.
c) Find the standard deviation of the set up cost.
d) If the next shipment is 40 bikes, what is the probability that the total set up cost will be less than $500?