Normal Approximation of the Binomial Distribution, example 2

In this video, we show show how to use the normal distribution to approximate binomial probability. We will use a typical z table along with the formulas for mean and standard deviation of a binomial random variable. Additionally, we will make use of something called continuity correction to improve the approximation.

[professor-wright]

ok. I think I sorta figured it out. I had to minus p-zTable-p:
21 = zTable: 31.55% zScore: 0.4804 mean: 19.5 stdev: 3.122
20.5 = zTable: 37.44% zScore: 0.4804 mean: 19.5 stdev: 3.122