This is a practice problem, I can't figure out?

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).

What is the point slope form of a line with slope -5 that contains point (2,-1)

9000 dollars is placed in an account with an annual interest rate of 8%. how much will be in the account after 17 years, to the nearest cent?