Question

Find P(not a 2)

x: 1, 2, 3, 4
p(X): 0.30, 0.40, 0.15, 0.15

Answer 1

P(not a 2) = P(1) + P(3) + P(4) = you can calculate

Answer 2

Yes, so its 0.30+0.15+0.15

or is it 0.30*1+0.15*3+0.15*4

Answer 3

It is your first expression. Your second expression is used when calculating the expected value.