00:01
Okay, so this problem says that children whose parents refused to participate in the randomized controlled slough trial got polio at a rate of 46 per 100 ,000, but children whose parents consented to participation got polio at a slightly higher rate of 49 per 100 ,000.
00:16
And this whole thing was repeated the next year, and based on this data, some parents refused to allow their children to participate in the experiment because they didn't want the children to be exposed to a higher risk of polio.
00:28
And the question is asking, are these parents right or not? and they want a brief explanation.
00:34
So these parents are not right because they aren't taking into account the certain confounding variable.
00:44
And that variable is family income.
00:53
On the surface, it may seem like those who participate in the trial get polio at a slightly higher rate.
01:02
But if you dig into it and actually think about it, those who participate, a lot of them will probably need the money for the, probably a lot of them are participating just for the money, and they need more money, so they probably have a lower family income, and thus they have less access to medical care...