1. ## discrete function help

$\displaystyle f(x)=(9/c)x^2$ for $\displaystyle x= 1,2,3,...,6$
For an appropriate value of c, we can define $\displaystyle P(X=x)=f(x)$

Find c so the functions is a pmf

So the outcome space has 6 values and its bounded? I don't know I'm completely lost

2. Originally Posted by Brokensound723
$\displaystyle f(x)=(9/c)x^2$ for $\displaystyle x= 1,2,3,...,6$
For an appropriate value of c, we can define $\displaystyle P(X=x)=f(x)$

Find c so the functions is a pmf

So the outcome space has 6 values and its bounded? I don't know I'm completely lost
since the distribution is discrete, the pmf sums up to 1

$\displaystyle \displaystyle \sum_{x=1}^{6} \dfrac{9}{c}x^2\;=\;1$

$\displaystyle \dfrac{1}{c}\displaystyle \bigg[\sum_{x=1}^{6} 9x^2\bigg]\;=\;1$

now find c

3. oh wow I'm a moron, Thanks for that I got it now haha