A graph has time (years) on the x-axis and height (inches) on the y-axis. A line goes through points (2, 5) and (4, 10).
The graph shows the height of a tree over time. What can you deduce the rate of change to be from 2 years to 4 years?
2 inch per year
2.5 inches per year
5 inches per year
10 inches per year

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?