In-Class Assignment # 2 03.20.12
Title the piece of paper “In-Class Assignment # 2 03.20.12”.
1. Battery manufacturers compete on the basis of the amount of time their products last in
cameras and toys. A manufacturer of alkaline batteries has observed that its batteries last
for an average of 26 hours when used in a toy racing car. The amount of time is normally
distributed with a standard deviation of 2.5 hours. What is the least amount of time that
24.6% of the batteries will last in a toy racing car?
2. A driver conducts an experiment in which they fill up their gas tank 40 times and they
record the average miles per gallon for each fill-up. The data indicates that the
population is normally distributed with a mean of 24.6 miles per gallon and a standard
deviation of 3.2 miles per gallon. What is the probability that the sample mean will be
greater than 23.4 miles per gallon?
3. The beef industry found that the per capita consumption of red meat in the U.S. in a
recent year was normally distributed, with a mean of 151.6 pounds and a standard
deviation of 46.3 pounds. If a person is selected at random, what is the probability that
they consumed between 150 to 154 pounds of red meat?