84 can’t be a perfect square
Simply plug in numbers!! (3x-1)(5)=55
15x-5=55
15x=60
x=4
hope this helps :)
It is the last answer choice
Answer: 7.94
Step-by-step explanation:
The formula to calculate the standard deviation for binomial distribution :-
, where n is the number total of trials and p is the probability of getting success in each trial.
Given : The probability of the population has a particular genetic mutation=0.1
If 700 people are randomly selected, then the standard deviation for the number of people with the genetic mutation in such groups of 700 will be :-

Hence, the standard deviation for the number of people with the genetic mutation in such groups of 700 = 7.94