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.
How long does it last? A: Semi-permanent color is ideal for trying a new hair color shade, and lasts through four to six shampoos. Used straight from the bottle, it contains no ammonia or peroxide, so it is mild enough to be used on fragile, permed or relaxed hair. It blends or covers gray (if hair is less than 25% gray); adds richness to natural hair color; gives highlights and shine, but does not lighten hair color. shop all semi-permanent color Back to Questions