Answer:
(D)109
Step-by-step explanation:
Mean = 450 seconds
Standard deviation = 50
First, we determine the probability that the expected response time is between 400 seconds and 500 seconds, P(400<x<500)
Using the Z-Score,
From the Z-Score table
P(-1<x<1) = 0.68269
The probability that the expected response time is between 400 seconds and 500 seconds is 0.68269.
Since there are 160 Emergencies
Number whose expected time is between 400 seconds and 500 seconds