Which table shows a proportional relationship? r 5 10 15 20 25 s 1 2 3 4 5 b 0 3 5 7 9 c 0 4 8 12 16 p 1 3 5 7 9 q 6 8 10 12 14 x 1 2 3 4 5 y 4 7 10 13 16

The length of time for one individual to be erved at a cafeteria is a random variable having an ex- ponential distribution with a mean of 4 minutes. what is the probability that a person will be served in less than/3 minutes on at least 4 of the next 6 days?