During the 3pm to 5pm time period cars arrive at a banks dri

During the 3pm to 5pm time period, cars arrive at a banks drive through window at an average rate of 15 customers per hour. Asuume that the time between arrivals follows the expotentional distribution. What is the probability that a randomly selected customer will arrive more than 10 minutes after the previous customer?

Solution

Given

mean=15

P(X>0.1667)=1-P(X<0.1667)( covert minutes to hours)

We use Excel to find P(X<0.1667.(use EXPON.DIST function)

P(X<0.1667)=0.9179

P(X>0.1667)=1-0.9179=0.082044