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.
Step-by-step explanation:
I'm not sure but that's what I'm getting 3k=2 jn simplest form
Answer:
I think it's a or b the picture is fuzzy
The number of hours required for 3 tractors to plow the field is 2.4 hours
<em><u>Solution:</u></em>
Given that 5 tractors can plow a field in 4 hours
We have to find out number of hours required for 3 tractors to plow the field
5 tractors can plow a field in 4 hours, So time taken for 1 tractor


<em><u>So time taken for 3 tractors is given as:</u></em>
time taken for 3 tractor = time taken for 1 tractor x 3


So number of hours required for 3 tractors to plow the field is 2.4 hours
Vertex is

and minimum value of f(x) is 12
Hope this helps