00:01
Okay, so in this problem we have to find the standard deviation.
00:03
The first step is to find the mean, second is to subtract the mean from each score, the third is square each deviation, the fourth step is to find the mean of the square deviation, and the fifth step is to take the square root of the mean of the square deviations to get the estimated standard deviation.
00:18
So we have our given scores, and we can calculate the mean.
00:21
So the mean is our given scores added up over the amount of values.
00:25
So that would be 2 plus 3 plus 4 plus 5 plus 6 plus 7 plus 8 all over 7, which equals to 35 over 7, which is equal to 5.
00:42
So that is our mean.
00:43
Mean is equal to 5.
00:46
Now we can find the deviations from the mean.
00:48
So the deviations from the mean for each score is 2 minus 5, 2 minus 5, 3 minus 5, 4 minus 5, 5 minus 5, 6 minus 5, 7 minus 5, and 8 minus 5.
01:10
So we're left with deviations of negative 3, negative 2, negative 1, 0, 1, 2, and 3.
01:21
So those are our deviations.
01:24
And so now we can square each deviation.
01:27
And so squaring a number by an even number is always going to give us a positive number, no matter if the number that we're squaring is negative or positive...