Empirical rule

The topic of  is under the Probability and statistics Math Mission. This exercise introduces the 68-95-99.7 rule for normal distributions.

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


 * 1) Find the probability: This problem describes a situation that can be modeled by a normal distribution. The student is asked to find the probability of an event using the empirical rule.Empirule1.png

Strategies
This exercise is easy to get accuracy badges because there is one general type of problem and the answers have to recycle quickly by necessity. The speed badges are easy especially if you have a generic picture drawn or can use a calculator to get the exact answer that is close to the empirical.
 * 1) If you draw a normal model, place the middle tick mark, and subdivide both sides by three additional tick marks, the size of each part are .0015, .0235, .135, .34, .34, .135, .0235, and .015.
 * 2) The only answers possible for above or below problems are: .0015, .025, .16, .5, .84, .975 and .9985.
 * 3) The only possible values for in between problems are: .0235, .1585, .475, .4985, .68, .815, .8385, .95, .9735 and .997.
 * 4) The calculator, if used, gives more precise answers which are close to but not exactly these values.