The amount of material used in making a custom sail for a sailboat is normally distributed with a standard deviation of 64 square feet. For a random sample of 15 sails, the mean amount of material used is 912 square feet.,. Which of the following represents a 99% confidence interval for the population mean amount of material used in a custom sail?
A)	912 49.2
B)	912 42.6
C)	912 44.3
D)	912 46.8
Answer:B
The amount of material used in making a custom sail for a sailboat is normally distributed with a standard deviation of 64 square feet. For a random sample of 15 sails, the mean amount of material used is 912 square feet.,. Which of the following represents a 99% confidence interval for the population mean amount of material used in a custom sail?
A)	912 49.2 B)	912 42.6 C)	912 44.3 D)	912 46.8