00:01
I'm going to start by filling out this table.
00:04
So my household sizes are 1, 2, 3, 4, 5, 6, 7.
00:12
And we're given a probability for each of these values of 0 .267, 0 .336, 0 .158, 0 .137, 0 .163, 0 .158, 0 .137, 0 .0 .0663, 0 .0 .0 .0663.
00:36
0 .024, and 0 .015.
00:45
I'm going to start with x times p of x, so multiplying each of these x values by its probability.
00:51
So 1 times .267, 2 times .336, 3 times .158, 4 times .137, 5 times .063, 6 times .0264, 24 and 7 times 0 .015.
01:28
Now to get our mean, all we have to do is just add up these values.
01:33
So that's going to give us a mean of 2 .525.
01:42
So now we're moving on to x minus the mean.
01:47
So we'll start with 1 minus 2 .525, 2 minus 2 .525, 2 minus 2 .525, 3 ,000.
02:06
Minus 2 .525, or minus 2 .525, 5 minus 2 .525, 6 minus 2 .525, and 7 minus 2 .525.
02:40
I'm going to square all those values, so negative 1 .525 squared, negative 0 .525 squared, 0 .475 squared, 0 .475 squared, 0 .475 squared, 2 .475 squared, 3 .475 squared, and 4 .475 squared.
03:29
And then finally, we're going to multiply each of those values by the corresponding probability.
03:45
So 2 .36 times 0 .276 times 0 .276 times 0 .336.
04:00
0 .226 .226 times .158.
04:13
2 .176 times .137, 6 .1226 times .036 times .036 .036 .026 .024...