SOLUTION: Can someone please tell me if I am correct so far and what I do to finish this problem please? The length of time a domestic flight must wait between gate departure and takeoff

Algebra ->  Probability-and-statistics -> SOLUTION: Can someone please tell me if I am correct so far and what I do to finish this problem please? The length of time a domestic flight must wait between gate departure and takeoff       Log On


   

Question 801195: Can someone please tell me if I am correct so far and what I do to finish this problem please?
The length of time a domestic flight must wait between gate departure and takeoff taxi at Boston’s Logan International Airport is approximately normally distributed with a mean of 20 minutes and a standard deviation of 5 minutes. What is the probability that a plane must wait between 18 and 24 minutes before taxiing for takeoff after leaving the gate?
z(18) = (18-20)/5 = -0.40 = .3121
z(24) = (24-20)/5 = .080 = .2881
.3121 - .2881 = .024
The probability that a plane must wait 18 and 24 minutes before taxiing is...I think it is 2.4% but I am not sure if I have done this correctly.
Thanks in advance!
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The length of time a domestic flight must wait between gate departure and takeoff taxi at Boston’s Logan International Airport is approximately normally distributed with a mean of 20 minutes and a standard deviation of 5 minutes. What is the probability that a plane must wait between 18 and 24 minutes before taxiing for takeoff after leaving the gate?
z(18) = (18-20)/5 = -0.40
z(24) = (24-20)/5 = +0.40
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Then::
P(18 <= x <= 24)
= P(0.3121 <= z <= 0.2881)
= normalcdf(-0.4,0.4)
= 0.3108
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Cheers,
Stan H.
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