Can someone help me out with this my grade are bad

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 y-intercept of the line given by the equation

The volume of a cone is 37x3 cubic units and its height is x units. which expression represents the radius of the cone's base, in units? 1 s o 3x o 6x obx 93x2