00:01
Okay, so this question says 500 draws are made at random from a box with 60 ,000 zeros and 20 ,000 ones.
00:19
So now we have a series of true or false questions with explanations.
00:25
So again, 500 draws are made.
00:27
So of part a it says true or false, the expected value for the percentage of ones among the draws is exactly 25%.
00:36
And that is true.
00:39
Here, i'll just write trf.
00:41
That is true because we have 20 ,000 ones and we have 80 ,000 cards total.
00:53
Well, we have 80 ,000 numbers total.
00:57
So that equals 25%.
00:58
So our expected value for the number of ones is exactly 25%.
01:04
For part b, it says the expected value for the percentage of ones among the draws is around 25%, give or take, 2 % or so.
01:14
And that's false because expected value is always an exact number.
01:20
It's not like around a number.
01:22
So that doesn't really make sense.
01:25
For part c, it says the percentage of ones among the draws will be around 25%, give or take, 2 % or so.
01:31
So let's see, the first part of that's definitely right.
01:33
It will be around 25 % because that's our expected value...