Question

A study found that the mean amount of time cars spent in drive-throughs of a certain fast-food restaurant was 150.5 seconds. Assuming drive-through times are normally distributed with a standard deviation of 34 seconds, complete parts (a) through (d) below. 

(a) What is the probability that a randomly selected car will get through the restaurant's drive-through in less than 93 seconds? 

The probability that a randomly selected car will get through the restaurant's drive-through in less than 93 seconds is (Round to four decimal places as needed.) 

(b) What is the probability that a randomly selected car will spend more than 204 seconds in the restaurant's drive-through? 

The probability that a randomly selected car will spend more than 204 seconds in the restaurant's drive-through is (Round to four decimal places as needed.) 

(c) What proportion of cars spend between 2 and 3 minutes in the restaurant's drive-through? 

The proportion of cars that spend between 2 and 3 minutes in the restaurant's drive-through is (Round to four decimal places as needed.) 

(d) Would it be unusual for a car to spend more than 3 minutes in the restaurant's drive-through? Why? 

The probability that a car spends more than 3 minutes in the restaurant's drive-through is _______ .so it be _______ unusual, since the probability is _______  than 0.05. (Round to four decimal places as needed.)

Answer 1