SOLUTION: 1-The length of time a domestic flight must wait between gate departure and takeoff taxi at Miami International Airport is approximately normally distributed with a mean of 20

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Question 1177230: 1-The length of time a domestic flight must wait between gate departure and takeoff taxi at Miami International Airport is approximately normally distributed with a mean of 20 minutes and a standard deviation of 5 minutes.
a. What is the probability that a plane must wait between 18 and 24 minutes before taxiing for takeoff after leaving the gate?
b. What is the probability a plane must wait between 22 and 30 minutes before taxiing for takeoff after leaving the gate?
c. What is the probability a plane waits more than 12 minutes between gate departure and takeoff taxi?
d. What is the length of time such that only 5% of planes wait this long or longer before gate departure and taxiing down the runway?
Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website!

Hi NOrmal Distribution: μ = 20min σ = 5min Using TI or similarly an inexpensive calculator like a Casio fx-115 ES plus a P( 18 < x < 24) = normalcdf(18,24, 20, 5) = .4436 b. P( 22 < x < 30)= normalcdf(22,30, 20, 5) = .3218 c. P( x > 12) = 1 - P(x ≤ 12) - 1 - normalcdf(-9999, 12, 20,5) = 1-.0548 = .9452 d. z = invNorm(.05) = 1.645= (x-20)/5 ⇒ x = 28.225min Wish You the Best in your Studies.