Consider the following distributions for a random variable X. In each case, match the distribution with the expectation of

Y = 10 - 2X²

For Poisson Dist lambda = 5

ForBinomial(n=10,p=0.3)

For Geometric p = 0.6

I'm not sure what I'm meant to do to get the RV "X". For poisson Im thinking mean = var = 5 so using Var = (X-E(X))^2. So 5 = (X - 5)^2 so X = 25 + 5^0.5

Then we just go Y = 10-2*(25 + 5^0.5)²

Is that the correct idea?