This is a Binomial distribution with probability of success p=0.55, n=10; you need to obtain probability of getting 4.
A salesperson has to sell a minimum of 50 cars to earn the sales bonus. To date this month he/she has sold 46 cars. Today the salesperson has appointments with 10 prospective customers. He estimates that he/she has a 55% chance of success with each customer.
What is the probability that he/she will earn his/her bonus today?
I am providing you with the probability mass function of Binomial distribution with parameters and . You just need to perform a suitable summation over it, taking appropriate upper and lower limits of .