Question

about 7% of the population has a particular genetic mutation. 400 people are randomly selected. find the mean for the number of people with the genetic mutation in such groups of 400.

Explanation:

Step1: Identify the binomial - distribution parameters

The binomial - distribution formula for the mean is $\mu = np$, where $n$ is the number of trials and $p$ is the probability of success on each trial. Here, $n = 400$ (the number of people selected) and $p=0.07$ (the probability that a person has the genetic mutation).

Step2: Calculate the mean

Substitute $n = 400$ and $p = 0.07$ into the formula $\mu=np$. So, $\mu=400\times0.07 = 28$.

Answer:

28