00:01
So for question five, we have that the probability density function, the probability density function, little f of x, can be found simply by taking the derivative of the cumulative density function, where the derivative rule that we'll be using here is that the derivative of x to the power of n with respect to x is always going to be n times x to the power of n minus one.
00:28
So for f of x in part five, we have that that is going to be, well, the derivative, oh, also i'll note that we have the rule that the derivative of a constant is simply equal to zero.
00:46
So we have that our probability density function is going to be zero.
00:54
If x is less than two, it's going to be 1 over 5 times 2x minus minus 0.
01:02
0, so just 1 over 5 comes 2x, or 2x over 5 for x between 2 and 3, and it's going to be 0 for x greater than 3.
01:25
Then, for part 6, we want basically for each one of these cumulative probabilities, all we need to do is take the appropriate value and plug it into our cumulative distribution function.
01:39
So x less than or equal to 2 .5 is going to be 1 over 2 times 2 .5 minus 1.
01:47
So that's going to be 1 over 2 times 1 .5.
01:52
Or that's going to be, i believe that's 0 .75...