HELP ME PLEASE WHAT IS THIS AND WHATS THE ANSWER EXPLAIN WHY DUE AT 10!!!

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).

2y= 3 2 x−2 y = − 1 3 x + 1 y=− 3 1 x+1

Which expression converts 45 degree to radians