Hi, the topic is Probability Density Function of a random variable.


For each of the following, find the constant c so that p(x) satisfies the condition of being a probability density function of a random variable X:
I. p(x) = c(2/3)^x, X E N
II. p(x) = cx,x E {1,2,3,4,5,6}

I can't state the right statistical symbols for every given. I'm sorry, so for clearer understanding of my given question, kindly refer to this image. http://i50.tinypic.com/5a2xxw.jpg
thank you

I've been figuring this for couple of days. Maybe a hint or step by step solution will do. Just guide me and I will solve this.