00:01
So in this question we have some data.
00:03
So for the ordinary story, this is population 1, we have reading times 7, 9, 8, 12, 7, 13, and 15.
00:17
Then for the own name story, this is population 2, sample 2, we have 4, 7, 15, 10, 3, and 7.
00:30
So in population 1 we have n1 is 1, 2, 3, 4, 5, 6, 7.
00:38
We have the sum over the data 7 plus 9 plus 8 plus 12 plus 7 plus 13 plus 15 is 71.
00:48
And the sum over the data squared is 7 squared plus 9 squared plus 8 squared plus 12 squared plus 7 squared plus 13 squared plus 15 squared, which is 781.
01:03
This allows us to calculate x -bar, which is the sum of x1 over n1.
01:11
So 71 over 7 is 10 .1429.
01:18
And s1 is root 1 over n1 minus 1, sum of the squares minus 1 over n1 times the sum of the x's squared.
01:28
That gives our summary sample statistics, sample variance, 1 over 6 times 781 minus 1 seventh of 71 squared, which is 3 .1848.
01:49
So those are our summary for population 1.
01:53
Population 2, we have n2 is 6.
02:01
The sum over that data is 4 plus 7 plus 15 plus 10 plus 3 plus 7, which is 46.
02:09
And the sum of the squares of the data, 4 squared plus 7 squared plus 15 squared plus 10 squared plus 3 squared plus 7 squared is 448.
02:20
This gives x -bar 1 is 46 over 6, which is 7 .6667.
02:31
And s1, sorry, x -bar 2, this should be, and s2 is the square root of one fifth of 448 minus one sixth of 46 squared, which is 4 .3665.
02:49
So that becomes our summary for population 2...