Can someone show me how to solve this?

1foot = 12 inches; 1 yard = 3 feet

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).

Acarton of juice contains 64 ounces miss wilson bought six cartons of juice how many ounces of juice did she buy