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.
Let the dye set. How long you should leave it in for will vary by brand, but 30 minutes to an hour is typical. Unlike permanent dyes, which contain harsh chemicals that can damage your hair and skin, there is usually no too long with semi-permanent colors. If you want to leave your work area while the dye sets, put your hair in a shower cap to keep from making a mess.