Question

Applications 17. The mean cost of domestic airfares in the United States rose to an all-time high of $385 per ticket (Bureau of Transportation Statistics website, November 2, 2012). Airfares were based on the total ticket value, which consisted of the price charged by the airlines plus any additional taxes and fees. Assume domestic airfares are normally distributed with a standard deviation of $110. a. What is the probability that a domestic airfare is $550 or more? b. What is the probability that a domestic airfare is $250 or less?

can you please include the formulas I would have to enter in to Microsoft excel to solve, thank you.

Answer 1

Using Excel:

Part a.

P(X>=550) = 1- P(X<=550)

We calculate P(X<=550) using Excel.

B6 - X V f =normdist(B2,B3,B4,TRUE) А с в Data provided 550 1 Descriotion 2 Value for which we need distribution x 3 Mean 4. Dstandard deviation 3851 110 5 6 Cumulation Distribution Function P(X<=x) =normdist(B2,B3,B4,TRUE)

Once Enter, We get the result below:

B6 X fx =NORMDIST(B2,B3,B4,TRUE) A 1 Descriotion 2 Value for which we need distribution x 3 Mean 4 Dstandard deviation 5 6 Cumulation Distribution Function P(X<=x) в Data provided 550 385 110 0.933192799

P(X>=550) = 1- P(X<=550)=1-0.9332=0.0668

Part b.

P(X<=250)

B6 D X for ENORMDIST(B2,B3,B4, TRUE) 1 Descriotion 2 Value for which we need distribution x 3 Mean 4 Dstandard deviation Data provided 250 385 110 5 6 7 Cumulation Distribution Function P(X<=x) 0.109860051

P(X<=250) = 0.1099

Hope this will be helpful. Thanks and God Bless You :)