The distribution of X is exponential with an average of 34. Suppose that you form random samples of size 26 from this distribution. Find the following, rounding probabilities to 4 decimals and everything else to 2 decimals. a. The average of X-bar is and the standard deviation of X-bar is For the following, use the average and standard deviation found in part a. b. Find P(X-bar > 42). b. Find P(30 < X-bar < 40). c. 40% of the averages are AT LEAST how much?

Assume that there is a 11% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?