Answer:
z-score = 2.
Step-by-step explanation:
The z-score = (x - m) / d where x =the person's score, m = the mean and d = the standard deviation.
So we have (87-67)/10
= 2.
First find out how much he makes in 8 hours (9x8=72). Then subtract 72 from 155 (155-72=83). Then divide 83 by 6 (83/6=13.8333). Since 83 is not evenly divisible by 6, and since he can't deliver .8333 of a delivery, we would round up, giving us 14). Ben would need to make 14 deliveries in 8 hours to make more than $155 :) Hope this helps you :)
