Police response time to an emergency call is the difference between the time the
ID: 3219352 • Letter: P
Question
Police response time to an emergency call is the difference between the time the call is first received by the dispatcher and the time a patrol car radios that it has arrived at the scene. Over a long period of time, it has been determined that the police response time has a normal distribution with a mean of 8.6 minutes and a standard deviation of 2.2 minutes. For a randomly received emergency call, find the following probabilities. (Round your answers to four decimal places.) (a) the response time is between 5 and 10 minutes (b) the response time is less than 5 minutes (c) the response time is more than 10 minutes
Explanation / Answer
for normal distribution z=(X-mean)/std deviation
hence a)P(5<X<10)= P((5-8.6)/2.2<Z<(10-8.6)/2.2)=P(-1.6364<Z<0.6364)=0.7377-0.0509=0.6868
b) P(X<5)=P(Z<-1.6364)=0.0509
c)P(X>10)=1-P(X<10)=1-P(Z<0.6364)=1-0.7377=0.2623