A distribution for the weights (in pounds) of a population of four year old boys is displayed below. The population has a mean of 40 pounds and a standard deviation of 3 pounds. Each of the other three graphs labeled A to C represent possible distributions of sample means for random samples drawn from the population. Which graph best represents a distribution of sample means for 600 samples each with a sample size of 5?

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?