# Statistics problem

• May 17th 2008, 05:30 AM
boab
Statistics problem
Hi, I was wondering if anyone could help with this part of a problem I'm working on.

A random variable is distributed between -1 and 1 according to the probability density function:

P(x)= Ax^4.

Find the value of A.

• May 17th 2008, 05:38 AM
mr fantastic
Quote:

Originally Posted by boab
Hi, I was wondering if anyone could help with this part of a problem I'm working on.

A random variable is distributed between -1 and 1 according to the probability density function:

P(x)= Ax^4.

Find the value of A.

One of the conditions for a function f(x) to be a pdf is $\int_{-\infty}^{+\infty} f(x) \, dx = 1$.
For your question this boils down to $\int_{x=-1}^{x=+1} A x^4 \, dx = 1$ ......