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 : 
Answer:
34
Step-by-step explanation:
$1.25 = 125 cents.
$42 = 4200 cents
Tickets sold at 75 cents = x
Tickets sold at 125 cents = y
x + y = 40
75x + 125y = 4200
Multiply the first equation by 75
75x + 75y = 3000
75x + 125y = 4200
Subtract the the second equation from the first.
75x + 75y = 3000
- 75x + 125y = 4200
-------------------------------
0 - 150y = - 1200
Divide both sides by - 150
-150y/-150 = -1200/-150
y = 8
Substitute y = 8 into the first equation
x + y = 42
x + 8 = 42
x = 42 - 8
x = 34
34 tickets were sold for 75 cents
8 tickets were sold for $1.25
The inequality that correctly represents this scenario is given as follows:

The graph is given at the end of the question.
<h3>What is a system of inequalities?</h3>
A system of inequalities is when two or more variables are related, and inequalities are built to find the values of each variable.
In this problem, the variables are given as follows:
- Variable x: number of chocolate chips purchased.
- Variable y: number of pecans sold.
Chocolate chips are $2 per pound and pecans are $5 per pound. She wants to spend at most $25, hence:

More can be learned about a system of inequalities at brainly.com/question/3656398
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