Question

Times for an ambulance to respond to a medical emergency in a certain town are normally distributed with a mean of 450 seconds and a standard deviation of 50 seconds.
Suppose there are 288 emergencies in that town.

In about how many emergencies are the response times expected between 400 seconds and 500 seconds?




a) 92

b) 98

c) 144

d) 196

Answer 1

Mean = 450 sec
standard deviation = 50 sec
450-50 =400
450+50=500

Between 400 sec and 500 sec means one deviation above and one deviation below the mean, and it is 68%.

68%=0.68
0.68*288= 195.84≈196 

Answer is d) 196