Question

For a pass or fail test, the probability of success is 10%. If 10 people complete the test, find the probability that 3 or more people will have a successful result.

Answer 1

Solution:

Given:

p = probability of success = 0.10

n = sample size = 10

We have to find P(X 3) = ...?

This can be written as,

P(X 3) = 1 - P(X 2)

Using Binomial probability distribution,

=0.3487+0.3874+0.1937

=0.9298

Therefore,

P(X 3) = 1 - 0.9298

P(X 3) = 0.0702

Hence, the probability that 3 or more people will have a successful result = 0.0702

Done