25
The triangle given by 9, unknown, and 15 and the triangle given by 15, unknown, and x are similar triangles and therefore 9:15 = 15:x
X is 25 in this case
The answer would be twenty five percent because four and one half is equal to seventy-five percent and one hundred minus seventy-five would be twenty-five.
Answer:
The standard deviation is of 8.586.
Step-by-step explanation:
For each person, there are only two possible outcomes. Either they have a genetic mutation, or they do not. The probability of a person having the mutation is independent of any other person, which means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
Probability of exactly x successes on n repeated trials, with p probability.
The standard deviation of the binomial distribution is:

About 9% of the population has a particular genetic mutation.
This means that 
900 people are randomly selected.
This means that 
Find the standard deviation for the number of people with the genetic mutation in such groups of 900.

The standard deviation is of 8.586.
Answer:
C.) I believe
Step-by-step explanation: