Question

In a survey of 1000 social-media account holders aged 18 years and older conducted by a certain organization, it was found that 78% of them have one or two such accounts. If 10 of the participants in the survey are picked at random, what is the probability that at most 7 of them have one or two social-media accounts? (Round your answer to four decimal places.)

Answer 1

We are given with
n = 1000
p = 0.78

Samples = 10
Condition = at most 7 have one or two social media accounts

We can use combinations to solve the problem
P = ∑10Ci (0.78)^i (1-0.78)^(10-i)/ 1000C10 from i from 0 to 7
Solve for P