1. ## Comulative distribution

Given the following comulative propability distribution:

0 if x less than zero
x/2 if x between 0 and 1
1-(1/(2x)^2) if x greater than one.
what's the probability P(X=1)? isn't it zero since a continuous variable don't have probability in a single point? cause my book says it's 1/4 and I'm confused about it... probably I'm mistaken...don't know

2. Originally Posted by Mppl
Given the following comulative propability distribution:
0 if x less than zero
x/2 if x between 0 and 1
1-(1/(2x)^2) if x greater than zero.
what's the probability P(X=1)? isn't it zero since a continuous variable don't have probability in a single point? cause my book says it's 1/4 and I'm confused about it... probably I'm mistaken...don't know
See the red above.
That is surely a mistake. It should be one.

Now the $P(X=1)=\frac{1}{4}$ because there 'jump' of that amount in the CDF at x=1.

3. ok got it now. Yes it was a mistake indeed. Thanks for the help