By the time we reach voting age, almost all Americans have at least a high school education. That means we have been exposed to numerous math courses, and hopefully passed them. But that does not mean we have a good sense of numbers. Innumeracy in the modern sense means that one does not have a good grasp of statistics and probability and how they impact one’s worldview. This article by FiveThirtyEight discusses a recent study of how little the blue and red teams know about each other, a prime example of how innumeracy is causing real problems in America.
Always sketch the normal curve situation first.
Remember the Standard Normal Distribution tables almost always give the area/probability from left infinity to the z-value in question; check for sketches on the tables you use to confirm. The Excel Norm.xxx functions also return the probability to the left of the z-value in question. If the problem asks for probabilities < x, you use the value directly from the table/function. If it asks for the probability > x, that is when you subtract the table/function value from 1.