(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The probability density function of a random variable y is:

f(y) = 100ye[itex]^{-10y}[/itex], if y>0

f(y) = 0 otherwise

What is the probability that 45y <= 10?

2. Relevant equations

E(y) = ∫yf(y)dy

Var(y) = ∫(y-E(y))f(y)dy

3. The attempt at a solution

I solved for the expected value of y and got E(y) = 0.2

I then got Var(y) = 0.02

I don't think this is a normal distribution because the PDF is not a normal

PDF. I don't know how to solve for the probability of 45y <= 10

Any help will be greatly appreciated!

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# How to solve for probability given density function

**Physics Forums | Science Articles, Homework Help, Discussion**