Select the correct answer.
Which statement is true?
A. Point estimates are used to make inferences about population parameters.
B. When we use the population mean and proportion to summarize information about the entire population, we call them point
estimates
C. The population mean and proportion are always equal to their corresponding point estimates,
D. The sample mean and sample proportion of a population are called population parameters.

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?