Answer:
Mean = 0.38082 checks per day
Variance = 0.38082
Standard deviation = 0.61711
Step-by-step explanation:
In a Poisson distribution, the variance (V) is equal to the mean value (μ), and the standard deviation (σ) is the square root of the variance.
A year has 365 days,, if 139 checks were written during a year, the mean number of checks written per day is:
Therefore, the variance and standard deviation are, respectively: