a. Find z such that 87.9% of the standard normal curve lies to the left of z. (Enter a number. Round your answer to two decimal places.)

z =

b. Find z such that 6% of the standard normal curve lies to the right of z. (Enter a number. Round your answer to two decimal places.)

z =

c.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 6.8 minutes and a standard deviation of 1.9 minutes. For a randomly received emergency call, find the following probabilities. (For each answer, enter a number. Round your answers to four decimal places.)

(a) the response time is between 3 and 8 minutes

(b) the response time is less than 3 minutes

(c) the response time is more than 8 minutes