Assistance on probability

Question

A business has Brand A, Brand B and Brand C of the same product. Market research has shown that 43% of costumers that purchase this product will choose Brand A. An organization conducts a poll of 100 consumers. Find the probability that 40 to 45 of the 100 consumers will prefer Product A, given the 43% brand preference is correct.

Answer 1

Ayobami

This is a binomial probability distribution with N= 100, p = 0.43

You need to find p (X=40) + p (X=41) + .... p (X=45)

p(X=n) = N C n pⁿ (1-p) ^N-n

N C n is the number of ways of choosing n things from N = N! / ( n!) (N-n) !

So you just need to calculate p(X=40), etc and add the terms together

Mike