00:01
Hey there, welcome to numerate.
00:03
So we have a rank sum test over here with sizes of 9 and 8.
00:08
So w is the sum of ranks for the first sample, which is 96 .5, and we had to find the z test statistic.
00:17
So the formula here that we will be dealing with is z equals.
00:22
Z will equal basically the w, the sum of ranks, minus the mean divided by the power.
00:38
Population standard deviation.
00:42
So to find population standard deviation here, or let's actually do the mean first, we're going to take the sample size and 1.
00:59
So n1 over here is 9.
01:07
So we take 9 multiplied by 8.
01:16
So we have actually 9 plus 8 plus 1.
01:24
This is going to be divided by.
01:32
And we're going to get a mean, let's calculate it here, 9 times 18, divided by 2 of 81.
01:46
So that was the mean.
01:47
Now we have to find our standard deviation here.
01:55
The equation for the standard deviation is basically going to be the square root of.
02:09
So what we're going to take over here is n1 and 2, so 9 times 8, multiple...