Using the Normal Distribution · Exercise 36

We flip a coin 100 times (n = 100) and note that it only comes up heads 20% (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% 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, Introductory Statistics 2e · §6.2 Using the Normal Distribution · Exercise 36