Write the sum using summation notation, assuming the suggested pattern continues. 4 - 12 + 36 - 108 + ...

summation of 4 times negative 3 to the power of the quantity n minus 1 from n equals 0 to infinity
summation of 4 times 3 to the power of the quantity n plus 1 from n equals 0 to infinity
summation of 4 times 3 to the power of n from n equals 0 to infinity
summation of 4 times negative 3 to the power of n from n equals 0 to infinity

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?