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.
Leaving color dye on your hair for longer than 45 minutes will not alter the color results, but may unnecessarily damage hair. Slight Color Change. If you are altering your current color by one or two shades (either lighter or darker), you may achieve desired results by leaving Color Charm on your hair for 30 minutes.