Answer: 0.0497870 ; 0.87754
Step-by-step explanation:
Given that :
λ = 0.0003
Defining a continuous distribution function :
F(x) = 1 - e^-λx = 1 - e^-0.0003x ; x ≥ 0
a. What proportion of the fans will last at least 10,000 hours?
P(x ≥ 10000) = e^-0.0003(10000) = 0.0497870
b. What proportion of the fans will last at most 7000 hours?
P(x ≥ 7000) = 1 - p(x ≤ 7000) = 1 - e^-0.0003(7000)
1 - 0.12245642825 = 0.87754
