Probability Mass Function

Hi,

I have a question:

Let X be a random variable with a given PMF of:

x | 0 | 2 | 4 | 5

p(x) |0.15 | 0.30 | 0.30 | 0.25

I need to calculate

P[ 2 < X < 4]

would this simply be 0? The question does not specify whether it is a discrete random variable or a continuous random variable.

In the event it is a continuous random variable, how do I find the answer?

thanks.

Re: Probability Mass Function

Quote:

Originally Posted by

**99.95** Let X be a random variable with a given PMF of:

x | 0 | 2 | 4 | 5

p(x) |0.15 | 0.30 | 0.30 | 0.25

I need to calculate

P[ 2 < X < 4]

would this simply be 0? The question does not specify whether it is a discrete random variable or a continuous random variable.

In the event it is a continuous random variable, how do I find the answer?

The *pmf* tells you that it is not a continuous random variable.

If it were then it has a completely different *pmf*.

Re: Probability Mass Function

ah, but of course!

Thanks.