We need to find the mean for the number of people with the genetic mutation in a group of 900.
We know that the probability of each person having that genetic mutation is 2%. Thus, this is a binomial distribution, with:
[tex]p=2\%=\frac{2}{100}[/tex]
Therefore, for a number n of people, the mean μ is given by:
[tex]\mu=n\cdot p[/tex]
Thus, for n = 900, we have:
[tex]\mu=900\cdot\frac{2}{100}=\frac{900}{100}\cdot2=9\cdot2=18[/tex]
Answer: 18
