Pleas hurry help Is it the median or mean?

9. {6.SP. A.2, 6.SP. A.3} Which reflects the best measure of the center? *
2, 4, 6, 8, 10, 15, 30

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).