Power +, Inc. produces AA batteries used in remote-controlledtoy cars. The mean life of these batteries follows a normaldistribution with a mean of 36 hours and a standard deviation of5.3 hours. As a part of its quality assurance program, Power +,Inc. tests samples of 9 batteries. a. What can you say about theshape of the distribution of the sample mean? Sample mean Roundanswers to four decimal places. b. What is the standard error ofthe distribution of the sample mean? Note: The standard error isthe standard deviation of the distribution of the sample mean. Thatis, the standard error is the population standard deviation dividedby the square root of the sample size. Standard error 0.7667 c.What proportion of the samples will have a mean useful life of morethan 37 hours? Probability d. What is the probability that arandomly selected AA battery will have a useful life of at most 34hours? Probability e. What proportion of the samples will have amean useful life between 34 and 37 hours? Probability
