Power+ produces AA batteries used in remotecontrolled toy cars The mean life of these batteries follows the normal probability distribution with a mean of 19 hours and a standard deviation of 5.3 hours. As a part of its testing program, Power+ tests samples of 25 batteries Use Appendix 3.1 for the zvaluesl a. What can you say about the shape ofthe distribution of sample mean? Shape of the distribution is (Click to select) v b. What is the standard error ofthe distribution of the sample mean? (Round the final answer to 4 decimal place.) Standard error c. What proportion of the samples will have a mean useful life of more than 20 hours? (Round the 2 values to 2 decimal places and the final answers to 4 decimal places.) Probability |:| d. What proportion of the sample will have a mean useful life greater than 18.5 hours? (Round the 2 values to 2 decimal places and the final answers to 4 decimal places.) Probability e. What proportion ofthe sample will have a mean useful life between 18.5 and 20 hours? (Round the 2 values to 2 decimal places and the final answers to 4 decimal places.) Probability