Afair spinner split evenly into 4 spaces has the values 2,5,6 and 10. find the variance

Let denote the value the spinner lands on. Then has PMF

Then the average value the spinner lands on is

and the variance is

We have

so that the variance is

hello from mrbilldoesmath!

answer:

the domain is the set { -2, 0, 2, 3}

discussion:

the domain is the set of x values in the ordered pairs (x,y). taking the x, or first component, of each ordered pair gives   -2, 0, 2, 3.

you,

mrb