00:01
Okay, so the supervisor of orange county is trying to do a sample, and first of all, they tell us that orange county has over 3 million adults.
00:10
Okay? we want to know what percentage of adults currently have covid -19 antibodies, and we have to consider that each participant will get a $100 amazon gift card for participating.
00:30
So we want to know what's the most appropriate way to get? samples.
00:34
So first of all, the first suggestion is collect a census.
00:38
That is definitely not going to work because that would be all three million people and if each one got $100, that would cost 300 million people plus there's going to be a lot of people who wouldn't want to participate anyways.
00:50
So that's definitely not going to be possible.
00:53
The second is to place a notice on social media platforms asking adults to volunteer.
01:04
That's definitely doable, although it won't give a random sample, right? number three, says select a random sample of adults with kaiser health insurance and ask if they would have their blood tested.
01:23
This is better because we're doing random sample.
01:26
So that's going to be better than this one, which is like you're going to have the self -sum.
01:30
Selection bias, right? the fourth one says select a random sample of adults using cell phone and home phone records and ask each if they would have their blood tested.
01:46
So this would be phone numbers and ask, right? and it also says random, so that's good, but it would take a really long time and a lot of people don't answer their phones anyway, so that would make it very difficult, right? so the best one is probably this one, where we use kaiser numbers to do a random sample.
02:10
B says with the context from above in mind, explain which sampling method would be best stratified method using cities as strata or a cluster method using age groups as the clusters...