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.
<h3>
Answer: 49</h3>
Work Shown:
Replace x with 3, replace y with -8. Use order of operations PEMDAS to simplify.
x^2 + y^2 + x*y
3^2 + (-8)^2 + 3*(-8)
9 + 64 - 24
73 - 24
49
Answer:
24
Step-by-step explanation:
if he eats 4 each day for 6 days, he will eat 24
4 × 6 = 24
<h2>
Answer with explanation:</h2>
A box contains 12 balls numbered 1 through 12.
Also the ball are drawn without replacement.
a)
The probability that the first ball had a smaller number on it.
i.e. the number on the first ball could be: {1,2,3}
Hence, the probability that the first ball had a smaller number on it is:

b)
The probability that the first ball has a even number on it is:
There are total 6 even numbers {2,4,6,8,10,12}
but 4 can't be considered as it comes on the second draw, so we are left with just 5 balls with even number.
Hence, the probability is:

I would help but not enough information sorry