Define the events
A = spinning any number but 4 (ie not getting 4)
B = flipping tails
For each event, the probabilities are:
P(A) = 4/5 because there are four numbers that aren't "4" out of five numbers total
P(B) = 1/2 assuming the coin is fair and each side is likely
P(A and B) = P(A)*P(B) is possible because the two events A and B are independent
So,
P(A and B) = P(A)*P(B)
P(A and B) = (4/5)*(1/2)
P(A and B) = (4*1)/(5*2)
P(A and B) = 4/10
P(A and B) = 2/5
The answer as a fraction is 2/5
In decimal form, the answer is 0.4