Answer:
0.183
Step-by-step explanation:
This is a question on Binomial Probability
Formula =nCx × p^x × q^n - x
p = 0.72
q = 1 - p
= 1 - 0.72
= 0.28
x = number of successes = 9
n = 10
The probability that at least nine out of ten people used an online travel website when they booked their airline ticket
At least 9 out of 10 means
x ≥ 9 = x = 9 and x = 10
Hence,
P(x ≥ 9) = 10C9 × (0.72^9 × 0.28^10 - 9) + 10C10 × ( 0.72^10 × 0.28^10 - 10)
P(x ≥ 9) = 0.14559635388 + 0.0374390623
= 0.18303541631
≈ 0.183
