Ch 7 HW Question 21

A study found that the mean amount of time cars spent in drive-throughs of a certain fast-food restaurant was 143.4 seconds. Assuming drive-through times are normally distributed with a standard deviation of 24 seconds. (Round to four decimal places as needed.)

I HAVE PART A AND B DONE I JUST NEED HELP WITH PART C. I AM PROVIDING A FOR BETTER HELP.

PART A

What is the probability that a randomly selected car will get through the restaurant's drive-through in less than 107

seconds?

The probability that a randomly selected car will get through the restaurant's drive-through in less than 107 seconds is 0.0643.

PART B

What is the probability that a randomly selected car will spend more than 183 seconds in the restaurant's drive-through?

The probability that a randomly selected car will spend more than 183 seconds in the restaurant's drive-through is 0.0495.

(Round to four decimal places as needed.)

PART 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)