00:03
So let's on x1, x2, up to xn, b the random variable is denoting n independent bits for an item that is for sale.
00:21
So we are going to suppose xi is uniformly distributed.
00:27
Sorry, is uniformly distributed on this interval.
00:39
So the probability density function of xi is given by this.
00:48
It is uniformly distributed.
00:51
We are going to get f of xi here x to be 1 over b minus a.
01:00
Why we know this is b and this is a.
01:03
So we have 200 minus 100.
01:07
So we have 1 over 100.
01:16
So the cumulative distribution function, which is the cdf, we have the cdf x i giving us big f of x i of x to be equal to x minus a over b minus a so we are going to get x minus hundred over 200 minus hundred so we have hundred over here where x belong to this interval we have hundred from a 200 and so we are going to let let y be the highest bit so we are going to get y to be equal to the max x i sorry x1 up to x n so x1 up to xn over here so our main name is to find for the expected value of x so you want to find for this over here so now the cumulative distribution function of y can be obtained as so the cdf of y so cdf of y can be obtained as f of y to be equal to p of y less than or equal to small y so we have p max x i where x i where i is from one up to n less than or equal to y so from here we are going to get an p of x i where x i is from one up to n less than or equal to y so from here we are going to get a p of x one less than or equal to y to p of x1 less than or equal to y um so we are doing this because um earlier we know um x i are independent so we know the x i are independent yeah so if they are independent it means we are going to get the product so we are going to use this instead so so i from 1 to n, the product of this.
04:12
So we have y minus 100, all over 100.
04:25
So f of y, which is the cumulative, will be equal to y minus 100, or divided by 100, or to the power n.
04:39
Where y belongs to 100, 200.
04:46
So i'm just enter one.
04:48
So now we can copy the probability density function of y by differentiating the cdf with respect to y...