# If the following is a probability distribution function: #f(x)=k(1/x^2)#, what is k and what is the variance?

##### 1 Answer

May 16, 2016

The Trick is to define the proper domain of the density.

#### Explanation:

Now the Integration is a piece of cake and the density fulfills the two properties for a density function:

#f(x)>0 AA x# #int_k^oof(x)dx=1#

The expected value