00:01
Okay, so firstly we're asked about the assumptions.
00:03
So the assumptions that we make are that the differences are approximately normally distributed, so the differences are approximately normally distributed, that the data is paired, and that each observation is independent.
00:27
Each person partaking in the before and after is independent of the other.
00:31
So are these met? well, since n is bigger than or equal to 30, then we can assume that the mean of the differences is indeed normally distributed.
00:44
And that's what we're after.
00:48
The paired data condition is satisfied because the same people are being measured with the image and without the image.
00:55
So this is satisfied.
00:57
And then independent, the sample is random.
01:01
So they should definitely be independent.
01:05
From one another.
01:08
And so we would pick option a, that yes, all conditions are met.
01:19
For the next question, we're then asked what the null and alternative hypotheses are...