Answer:
Im not sure
Step-by-step explanation:
GOOD LOOK ON YOUR TEST HE DISCONN-ECTED
Answer:
most common, 4, c, 9
Step-by-step explanation:
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 : 
I think what you need to do is make B = -5
3a = -2(-5) - 7
3a = 10 - 7
3a = 3
a = 1