Please help everything you need is on the picture.

Fractions can be added and subtracted only if they're fractions. a. like b. proper c. improper d. unlike

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).

Divide the following fractions 3/4 ÷ 2/3 1/2 8/9 9/8 2