Given that X1 = 2.3, X2 = 1.9 and X3 = 4.6 is a random sample from

fX(x) =x^3e^(-x/a)6a^4

for x greater than or equal to 0, calculate the MLE for a.

also, can anyone tell me how to copy and paste formulas such as the one above into the question on this website? i hate how messy it looks like this...thanks