View Full Version : disctrete or cumulative ??

04-06-2010, 07:40 PM
0 if x <2
0.7 if 2 <= x < 2.5
F(x) = 0.8 if 2.5 <= x < 3
1 if x => 3

from first sight i think that this is a cumulative function
but then I saw that
P(x) > 1 if negative infinity < x < infinity.
i dont no if that matters though maybe i have the concept
of cumulative distribution completly wrong lol

thanks for any help

actually figured it out the function is not continous, so is not a distribution for a continuous random variable.
It is a distribution for a discrete random variable, but i dont know what the probability function would be;

04-06-2010, 11:17 PM
It could be the c.d.f. of a continuous random variable. The p.d.f. can take values greater than 1 so long as the integral over which it is defined equals 1.

04-07-2010, 12:50 AM
It is the cumulative distribution function.

That means the probability in 2.5 <= x < 3 is 0.1 (=0.8-0.7).