Answer: The mean number of checks written per day

Standard deviation

Variance

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 :
