Answer:
47.72%
Step-by-step explanation:
Given
Mean (u) = 15
SD = 4
P(15<x<23) = 
= 
=P(0<z< 2)
=P(z<2) - P(z<0)
Use standard normal table to find probability of the z score
= 0.9772 - 0.5
= 0.4772 
47.72%
Answer:
2
Step-by-step explanation:
So let's call the time she needs to catch up "x", and so Terry's rate would be x-6 since he left home 6 hours earlier. Then we multiply the rates to get 20x - 120 = 80x. The answer is -2, but we can just say 2.
Checking our answer, that means if it took Sally 2 hours, it took Terry 8 hours for he left home 6 hours earlier. So 8 times 20 = 160km traveled. 2 times 80 = 160km traveled. Same distance.
