Let x be the discrete random variable whose value is the number of successes in n trials.
The probability distribution function for x of the binomial distribution B(n,p) is defined as
![B(n,p)= nC_xp^x(1-p)^(n-x)](https://img.qammunity.org/2019/formulas/mathematics/college/u60hn366bc69xmgjbpyy6wkh7dbsu26fhu.png)
Given that the random sample size is
![n=25](https://img.qammunity.org/2019/formulas/mathematics/college/u0cjcv3bjnx3o9jv5kmtp4rxziodozbqhi.png)
let x represent number of customers who purchase running shoes
Let "p" be the probability of customers in a sporting goods store purchase a pair of running shoes.
It is given that 70% of the customers in a sporting goods store purchase a pair of running shoes.
Thus
![p=(70)/(100)=0.7](https://img.qammunity.org/2019/formulas/mathematics/college/a6rwcq9qkm98o75gtjd9ft7najcflg85xf.png)
Thus the Probability distribution of x is given by
, where
![x=0,1,2,3,...,25.](https://img.qammunity.org/2019/formulas/mathematics/college/nau536tjq7i30z3f1c1nfomd0tlrdbtxfr.png)