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Part 1
A study found that the mean amount of time cars spent in drive-throughs of a certain fast-food restaurant was 139.3 seconds. Assuming drive-through times are normally distributed with a standard deviation of 32 seconds, complete parts (a) through (d) below.
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Part 1
(a) What is the probability that a randomly selected car will get through the restaurant's drive-through in less than 85 seconds?
The probability that a randomly selected car will get through the restaurant's drive-through in less than 85 seconds is
enter your response here.
(Round to four decimal places as needed.)
Part 2
(b) What is the probability that a randomly selected car will spend more than 178 seconds in the restaurant's drive-through?
The probability that a randomly selected car will spend more than 178 seconds in the restaurant's drive-through is
enter your response here.
(Round to four decimal places as needed.)
Part 3
(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
enter your response here.
(Round to four decimal places as needed.)
Part 4
(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
enter your response here, so it
▼
would
would not
be unusual, since the probability is
▼
greater
less
than 0.05.
(Round to four decimal places as needed.)
