Question

A coin is tossed 10 times. What is the probability that the number of heads obtained will be between 5 and 7 inclusive? Express your answer as a fraction or a decimal number rounded to four decimal places. E Tables да Кеур Answer How to enter your answer Keyboard Show Subm Hawkes Learning

Answer 1

P(head) = 0.5

n = 10

P(5, 6 or 7) = P(5) + P(6) + P(7)

$P(x) = \frac{N!}{x! (N-x)!} \pi ^{x} (1-\pi)^{N-x}$

$P(5) = \frac{10!}{5! (10-5)!} 0.5 ^{5} (1-0.5)^{10-5} = 0.24609375$

$P(6) = \frac{10!}{6! (10 - 6)!} 0.5 ^{6} (1-0.5)^{10-6} = 0.205078125$

$P(7) = \frac{10!}{7! (10 - 7)!} 0.5 ^{7} (1-0.5)^{10-7} = 0.1171875$

P(5, 6 or 7) = P(5) + P(6) + P(7) = 0.5684

ANS: 0.5684