using the Poisson distribution to determine the probability that a page contains exactly 2 errors is 0.0163
Solution:
Given that, A book contains 400 pages.
There are 80 typing errors randomly distributed throughout the book,
We have to use the Poisson distribution to determine the probability that a page contains exactly 2 errors
The poisson distribution is given as:


And, k = 2 errors.
Plugging in values in poisson distribution, we get

On solving, we get
= 0.0163
Hence, the probability is 0.0163.