Answer:
exact form: 13/5
Decimal form: 2.6
x= 2 3/5
Step-by-step explanation:
3x+4x-7=8-3x+11
7x-7=8-3+11
7x-19-3x
7x-7 + 7 =-3x+19+7
7x=-3+26
10x=26
x= 13/5
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 : 
Y=3x−9
y=3(0)-9
y=9
Now plug in y to solve for x.
y=3x−9
9=3x-9
18=3x
6=x
The x-intercept is (6,0)
The answer is 1.47
hope this help you
So you can buy $4 pack of $800 each, or buy $7 packs of $500 each.