00:01
All right, so we have a study that the super sneaker company conducted where they had two groups of 12 high school students.
00:13
And after obtaining their shoe sizes, the company manufactured 12 pairs of shoes for group 1, where each pair with both souls were constructed from material a and 12 pairs of shoes for group 2, where each pair with both souls constructed for material b.
00:29
After three months, the amount of sole wear in each pair of both souls were constructed from material a.
00:32
Shoe was recorded in standardized units.
00:38
And so the researcher in charge of this design only wanted one measurement of shoe wear per student.
00:46
And to get only one measurement per student, there were a few different options.
00:51
And so the researcher chose this third option averaging the left and right shoe wear for each pair because it used information from both left and right equally.
01:05
Is people are different.
01:07
Some people walk more on the left, different ways of walking or various reasons.
01:14
You could have more where on the other than she went than the other, so she just wanted one number, so just average than both.
01:22
So using option three, the following data were used to test the hypothesis for where, that where for material b was greater than that for material a.
01:37
But we're asked here, for the null hypothesis and it's tricky because they have all these symbols like all these you know here's the population mean here's the sample mean symbols but it's kind of hidden down here but it's this one the null would be that the means are equal sometimes you'll see it is is this so you b equals mua but if we think about the alternative well you can also view this as as mu b minus mu a equal these are the same right that's they they're equal that means the difference is zero and the same thing in the alternative it's not being asked you but it's just good to see it they're testing whether the where for material b was greater than that for a that the mean of b is greater of a, which would correspond to the mean of b minus mean of a is greater than zero...