An airline company is considering a new policy of booking as many as 318 persons on an airplane that can seat only 310. (Past studies have revealed that only 90% of the booked passengers actually arrive for the flight.) Estimate the probability that if the company books 318 persons. not enough seats will be available.

Respuesta :

Answer:

Hence, the required probability is [tex]0.0004[/tex].

Given :

[tex]90\%[/tex] of the booked passengers arrive for the flight.

Number of booked passengers n [tex]=318[/tex]

Number of seats available x [tex]=310[/tex]

To find :

The probability that if the company books 318 persons.

Explanation :

[tex]n=318,x=310[/tex]

[tex]P=0.09(90\%)[/tex]

Mean  [tex]\bar{x}=nP[/tex]

   [tex]\Rightarrow \bar{x}=318\times 0.09[/tex]

  [tex]\Rightarrow \bar{x}=28.62[/tex]

Standard deviation [tex]\sigma =\sqrt{nPq[/tex]    where [tex]q=1-P[/tex]

         [tex]\Rightarrow \sigma =\sqrt{318\times 0.09\times 0.91}[/tex]

        [tex]\Rightarrow \sigma=\sqrt{26.0442}[/tex]

        [tex]\Rightarrow \sigma =5.1033[/tex]

Required probability[tex]=P(x>310)[/tex]

                                 [tex]=1-P(x<310)[/tex]

                                [tex]=1-P(\frac{x-\bar{x}}{\sigma}<\frac{310-28.62}{5.1033})[/tex]

                               [tex]=1-P(z<55.1368)[/tex]

                              [tex]=1-0.9995[/tex]

                               [tex]=0.0004[/tex]