B E
Becca surveyed the students at her school to find out which cellphone company they use. Her results are listed in the table.
Freshman Sophomore Junior Senior Total
27
34 24 18 103
10
15 43
110
Company A
Company B
Company
Total
40
36
34
30
140
77
SS
101
90
353
What is the probability that a randomly chosen student is a junior who uses company B?
43
353
43
A
D
101
E.
43
110
110
O a 10

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?