Z-scores 2

The topic of  is under the Probability and statistics Math Mission. This exercise calculates probabilities from a standard normal table.

Types of Problems
There is one type of problem in this exercise:


 * 1) Find the probability using the table: This problem describes a normal distribution with a mean and a standard deviation. It asks the student to calculate the probability that a score would be above or below a particular value.Zscore2-1.png

Strategies
This exercise is medium to get accuracy badges because you first need to learn how to use the standard normal table. Once this is done, the speed badges are easy because you only need to look in the table a single time.
 * 1) You will have to calculate the z-score to look it up in the table. The formula to find the z-score is to take the value, and calculate $$ (x-\mu)/ \sigma $$.
 * 2) If the problem wants "below a positive z-score" the answer is the number in the table.
 * 3) If the problem wants "below a negative z-score" the answer is the number in the table subtracted from one.
 * 4) If the problem wants "above a z-score," first calculate "below a z-score" as in the previous two points, then subtract that answer from one.