A = 1/2bh...for h
multiply both sides by 2
2A = bh
now divide both sides by b
(2a)/b = h
The answer is,
"52 thousandths = 0.052
5.2 x 10^-2"
Since

, we know that

follows a Poisson distribution with parameter

.
Now assuming

denote the mean and standard deviation of

, respectively, then we know right away that

and

.
So,
Enjoy
200,000 + 80,000 + 3,000 + 900 + 80