Using the Normal Distribution · Exercise 36

We flip a coin 100 times (n = 100) and note that it only comes up heads 20 percent (p = 0.20) of the time. The mean and standard deviation for the number of times the coin lands on heads is µ = 20 and σ = 4—verify the mean and standard deviation. Solve the following:

(a) There is about a 68 percent chance that the number of heads will be somewhere between ___ and ___.
(b) There is about a ____chance that the number of heads will be somewhere between 12 and 28.
(c) There is about a ____ chance that the number of heads will be somewhere between eight and 32.

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Statistics · §6.2 Using the Normal Distribution · Exercise 36