What is Cumulative Binomial probabilities? I am new to this so don't know if I am asking the right question as I just read about its usage but didn't know what exactly a Cumulative Binomial probability is.
So my question is, What is Cumulative Binomial probabilities ? any example will be of great help.
Thanks! :)
 A: I guess you mean the cumulative distribution function $F(k;n,p)$ of the
(discrete) binomial distribution with number of trials $n \ge 0$ and success probability $0 \le p \le 1.\;$
The probability mass functions (PMF)  is
$$f(k;n,p) = \binom{n}{k}p^k(1-p)^{n-k} $$
and the CDF can be expressed with
normalized incomplete Beta function
$$F(k;n,p) = \sum_{i=0}^{k}f(k;n,p) =  I_{1-p}(n-k,k+1)$$
A: I sense that you are implicitly asking what a cumulative density function is. I apologize if this is not the case, and you can ignore what follows.
Imagine that your Binomial random variable represents the number of heads you obtain while flipping some coin $n$ times (let's formally call this random variable $X$). Then, the cumulative density function (or CDF) is a function that tells you, for each natural number $k$, what is the probability that you will obtain 
at maximum $k$ heads. If your coin is biased and it has a probability of showing heads equal $p$, the definition the CDF is
$F(k) = \mathbb P (X \leq k)$.
This definition is general, it works for all random variables and not only Binomials! For the specific Binomial case, gammatester gave you the correct formula.
