Normal Distribution and z-scores. mean: the average obtained by dividing the sum of the data by the number of data in the set. Given a set of data, {x 1, x 2, x 3, ..., x n }, you can find the mean, , using the following formula: standard deviation: the extent to which data differs from the mean.
Quick Answer. Kool-Aid hair dye hair dye can last for eight to 12 weeks. The intensity of the color depends on several factors such as the natural hair color, the amount of time the hair is soaked with the dye, the amount of dye used and the dyeing method used. Continue Reading.
If you've decided that you no longer want the color in your hair, here are some possible ways of removing it. 1  1. Wash your hair more often. Kool-Aid dye can take between one month to three months to wash out, depending on your natural hair color. 2  2. Use baking soda for long hair only.