00:01
On this problem, we are told that we are given a probability density function of one -half where x lies between 1 and 3.
00:11
Now, in a, we want to show that the area under the curve is equal to 1.
00:15
Now, finding the area under the curve just means find the antiderative here.
00:19
And so we integrate this from 1 to 3.
00:27
And so this is 1 -half x, max goes from 1 to 3, which is 3 -5, which is 1.
00:38
And so we showed that the area under the curve is in fact 1.
00:43
On b, we want to find the probability that 2 is less than x is less than 2 .5.
00:58
Now this is equal to the integral from 2 to 2 .5 of our probability density function.
01:09
So this is 1 half x evaluated from max equals 2 to 2 .5...