Suppose that a population has 30 of individuals displaying a

Suppose that a population has 30% of individuals displaying a particular phenotype*. In repeated random samples of 400 individuals, the sample proportion p would follow a Normal distribution with mean *Note: A phenotype is the set of observable characteristics of an individual resulting from the interaction of its genetic constitution of an individual organism. with the environment.

Solution

the sample proportion p would follow a Normal distribution with mean

we need to use the formula for the binomial distribution with aproximation of normal distribution

mean will be p * n

0.30 * 400 = 120

mean = 120