00:01
We have a 500 -page document and we have the number of errors.
00:04
And so this is our heirs and this is the frequency of those errors.
00:08
And we have 0, 1, 2, 3, 4, 5.
00:11
And we have 102, 138, 140, 79, 33, and 8.
00:21
And so on part a, we want to find the mean.
00:24
Let's do that in red.
00:25
And we find the mean as we have zero occurring, 102 times.
00:31
We have one occurring 138 times, two occurring 140 times, 3 79 times, 4 occurring 33 times, and 5 occurring 8 times.
00:45
And we need to add up all of those numbers and divide by how many we have, which is 500.
00:50
And when we get that total, we have our value as one point, our average, or our mean is 1 .654.
01:03
And so now we want to find our sample standard deviation, our s.
01:08
And we know that that's going to be a big square root, because if we don't square root, we have variance.
01:14
And we know we are going to add up all of those squared deviations, and we have 499 of them.
01:22
So we're going to take zero minus this number, and that deviation is negative.
01:27
But since we're squaring it, i'm going to just put it as positive...