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.
Permanent hair dye lasts up to eight weeks. A hair dyeing kit. Semi-permanent hair dye cannot be used to lighten hair. Henna can be used to make a semi-permanent hair dye. Semi-permanent hair color lasts about six weeks or up to about 24 shampoos. When dying hair, it's recommended to wear gloves to prevent staining the hands.