# Question: Fast food restaurants spend quite a bit of time studying the

Fast-food restaurants spend quite a bit of time studying the amount of time cars spend in their drive-throughs. Certainly, the faster the cars get through the drive-through, the more the opportunity for making money. QSR Magazine studied drive-through times for fast-food restaurants and found Wendy’s had the best time, with a mean time spent in the drive-through of 138.5 seconds. Assuming drive-through times are normally distributed with a standard deviation of 29 seconds, answer the following.

(a) What is the probability that a randomly selected car will get through Wendy’s drive-through in less than 100 seconds?

(b) What is the probability that a randomly selected car will spend more than 160 seconds in Wendy’s drive-through?

(c) What proportion of cars spend between 2 and 3 minutes in Wendy’s drive-through?

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

(a) What is the probability that a randomly selected car will get through Wendy’s drive-through in less than 100 seconds?

(b) What is the probability that a randomly selected car will spend more than 160 seconds in Wendy’s drive-through?

(c) What proportion of cars spend between 2 and 3 minutes in Wendy’s drive-through?

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

**View Solution:**## Answer to relevant Questions

The lengths of human pregnancies are approximately normally distributed, with mean µ = 266 days and standard deviation σ = 16 days. (a) What proportion of pregnancies lasts more than 270 days? (b) What proportion of ...In games where a team is favored by more than 12 points, the margin of victory for the favored team relative to the spread is normally distributed with a mean of -1.0 point and a standard deviation of 10.9 points. (a) In ...The ACT and SAT are two college entrance exams. The composite score on the ACT is approximately normally distributed with mean 21.1 and standard deviation 5.1. The composite score on the SAT is approximately normally ...Suppose X is a binomial random variable. To approximate P(3 ≤ X ≤ 10), compute ____________. The probability that more than 500 adult Americans support a bill proposing to extend daylight savings time A discrete random variable is given. Assume the probability of the random variable will be approximated using the ...Post your question