Question 876046
Find exact probabilities showing all required computation.
Five fair coins are tossed. Find the probability of the coins showing;

Let X = number of heads appearing on tossing a fair coin five times. 
X~Binomial(5, 0.5)

A: At least four heads
P(X ≥ 4) = {{{sum((matrix(2,1,5,x))(0.5^5), x = 4, 5)}}} = {{{highlight(0.1875)}}}

B: At least three heads
P(X ≥ 3) = {{{sum((matrix(2,1,5,x))(0.5^5), x = 3, 5)}}} = {{{highlight(0.5)}}}

c: At least two heads
P(X ≥ 2) = {{{sum((matrix(2,1,5,x))(0.5^5), x = 2, 5)}}} = {{{highlight(0.8125)}}}

D: At least one head
P(X ≥ 1) = {{{sum((matrix(2,1,5,x))(0.5^5), x = 1, 5)}}} = {{{highlight(0.96875)}}}