Question

17) A paint manufacturer discovers that the mean volume of paint in a gallon-sized pail is 1 gallon with a standard deviation of 0.1 gallons. The paint volumes are approximately bell-shaped (normally distributed). Estimate the percent of pails with volumes between .70 gallons and 1.30 gallons.

21) The average length of crocodiles in a swamp is 10.5 feet. If the lengths are normally distributed with a standard deviation of 1.3 feet, find the probability that a crocodile is more than 10 feet long.

Answer 1

17) µ = 1

                                      

                                       = P(-3 < Z < 3)

                                       = P(Z < 3) - P(Z < -3)

                                       = 0.9987 - 0.0013

                                       = 0.9974

21) µ = 10.5

                        

                         = P(Z > -0.38)

                         = 1 - P(Z < -0.38)

                         = 1 - 0.3520

                         = 0.6480