Question

In a certain city, the daily consumption of electric power
(in millions of kilowatt hours) is a random variable having:
f(x)=(1/9x)e^(-x/3) for x>0
0 for x<= 0

If the city's power plant has a daily capacity of 12 million
kilowat hours, what is the probability that this power supply
will be inadequate on any given day?

Answer 1

I'm unsure of how to set up the limits for this.

Answer 2

I'm going to rewrite the pd:
\[f(x)= \frac{ 1 }{ 9 }xe^{\frac{ -x }{ 3 }}=.1111xe^{-.3333x}\]