# Homework Help: Finding constant in Probability density function.

1. May 25, 2012

### sid9221

A continuous random variable X has pdf:

$$f_X(x)=\left \{ k(x+3), 0\leq x\leq 1\right \}$$

0 otherwise.

Find k.

I solved the integral (from 0..1) and solved for the result equal to 1.

Hence I got k=2/7.

Is this the right way to proceed as the question continues and I want to check if I'm starting correctly

2. May 25, 2012

### lanedance

yep, you just want to normalise to 1

3. May 25, 2012

### sid9221

What do you mean normalize to 1 ?

It was 7/2k=1
So k=2/7

?

4. May 25, 2012

### Ray Vickson

Normalizing means making $$\int_0^1 f_X(x) \, dx = 1.$$

RGV