Answer:
a)0.067
b)0.111
c)0.612
d)$687.28
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = $385
Standard Deviation, σ = $110
We are given that the distribution of domestic airfares is a bell shaped distribution that is a normal distribution.
Formula:
a) P(domestic airfare is $550 or more)
P(x > 550)
Calculation the value from standard normal z table, we have,
b) P(domestic airfare is $250 or less)
Calculating the value from the standard normal table we have,
c))P(domestic airfare is between $300 and $500)
d) P(X=x) = 0.03
We have to find the value of x such that the probability is 0.03.
P(X > x)
Calculation the value from standard normal z table, we have,
Hence, the domestic fares must be $687.28 or greater for them to lie in the highest 3%.
