Answer: 0.74
Step-by-step explanation:
Given : The probability that the passengers booked for a certain flight actually show up : p=0.80
The number of passengers are randomly selected : n= 9
Binomial probability formula to find the probability of getting success in x trial :-
[tex]P(x)=^nC_xp^x(1-p)^{n-x}[/tex]
Then , the probability that more than 6 of them show up will be :-
[tex]P(x>6)=P(7)+P(8)+P(9)\\\\=^9C_7(0.8)^7(0.2)^{2}+^9C_8(0.8)^8(0.2)^{1}+^9C_9(0.8)^9(0.2)^{0}\\\\=\dfrac{9!}{7!(9-7)!}(0.8)^7(0.2)^{2}+(9)(0.8)^8(0.2)+(1)(0.8)^9\approx0.3020+0.3020+0.1342=0.7382\approx0.74[/tex]
Hence, the probability that more than 6 of them show up = 0.74