Since this is a linear function, filling in the minimum and maximum of the domain is sufficient.
f(-4) = -16 + 9 = -7
f(2)= 8 + 9 = 17
So the range of the function (given the domain) :
R = {-7, 17}
Answer: The mean number of checks written per day 
Standard deviation
Variance 
Step-by-step explanation:
Given : The total number of checks wrote by person in a year = 126
Assume that the year is not a leap year.
Then 1 year = 365 days
Let the random variable x represent the number of checks he wrote in one day.
Then , the mean number of checks wrote by person each days id=s given by :-

Since , the distribution is Poisson distribution , then the variance must equal to the mean value i.e. 
Standard deviation : 
Are you trying to figure out the value of n?
Answer:
14x + 23
Step-by-step explanation:
The lengths of three sides of a triangle are 5x + 9 feet, 2x + 14 feet, and 7x feet.
The perimeter of a triangle: the sum of all of its sides.
5x + 9 + 2x + 14 + 7x
14x + 23
It's the expression of the perimeter of the triangle. Once you will be asked to find x, you'll probably be given the exact perimeter of the triangle.