Abaseball coach gives half his players an energy drink to consume before each game; the other half does not receive the energy drink. after a month of games, he analyzes their playing stats. he concludes the energy drink improve their performance on the field. how can the coach test the means to be sure his results are not likely to happen by chance?

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?