00:01
Hey there, welcome to numeraid.
00:03
We are asked to find the probability that between 40 and 50 of the selected items would be defective here.
00:11
So we first have to calculate what is our mean and standard deviation.
00:17
So for our mean, we know we have n times p, the number of trials times the probability.
00:24
So 400 times 0 .1, which equals 40.
00:28
And we have the square root of n times p times the complement.
00:36
So hence, this will give us a standard deviation of 6, plugging everything in.
00:42
Now, what we're trying to find here is the probability.
00:47
So actually, let's put this on top...