00:01
So our lambda value, first of all, that's going to be n times p.
00:06
So we're just going to take 400 trials and multiply it by the probability of a success.
00:10
So 400 times 0 .02, we get that lambda is going to be 8.
00:17
So that's lambda.
00:19
And now we want to use the poisson distribution to estimate the probability of r equals 8 successes.
00:24
So what we're going to do is plug it into the formula.
00:28
It's just going to be lambda to the x over x factorial e to the negative lambda.
00:37
And in this case, x is like our desired number of successes, so 8 in this case.
00:42
So we're going to have 8 to the 8 over 8 factorial e to the negative 8.
00:52
So now we can just type this in our calculator.
00:56
8 to the 8th power...