a) The amusement park administration chain has studied its customers to determine how

much money they spend on concessions. The study revealed that the spending

distribution is approximately normally distributed with a mean of $4.11 and a standard

deviation of $1.37. Use the unit normal distribution area table to find the percentage of

customers spend less than $3.00 on concessions?

b) Let X be normally distributed with mean and standard deviation . So that P(X 45) =

0.90 and P(X 84) = 0.05. Use the unit normal distribution area table to find and .

c) The heights of candidates to the military force are normally distributed with mean 165 cm

and standard deviation 2.5 cm. If 30% of applicants are rejected because they are too

small, Use the unit normal distribution area table to find the minimum acceptable height

for the military force?