The number of different mathematics courses at community colleges has a Poisson Distribution with a mean of 20 courses per college. *show your basic keystrokes and round your answer to 4 decimal...

The number of different mathematics courses at community colleges has a Poisson Distribution with a mean of 20 courses per college.

*show your basic keystrokes and round your answer to 4 decimal places.

1. What is the probability there will be fewer than 38 courses at 2 colleges?

Someone on this site already answered this question, but I don't understand what they did, how they got the number 40 for this problem to solve it. Can you help me understand this please? I also didn't know if this was poissoncdf or poissonpdf.

Extracted text: Step 4 2. Probability that there wil be fewer than 38 courses at 2 colleges: If X and Y are two independent Poisson random variables with mean A1 and n2 then, the random variable Z-X+Y have a Poisson distribution with me2 Let the random variable Z denotes the number of different mathematics courses at two colleges and it has mean 40. The required probability is, P(XtY-Z-38). That is, 3740 C-0 0.3547 Using the Excel function, POISSON.DIST(37,40,TRUE)