mean deviation

mean deviation : In statistics, the absolute deviation of an element of a data set is the absolute difference between that element and a given point. Typically the point from which the deviation is measured is a measure of central tendency, most often the median or sometimes the mean of the data set. where Several measures of statistical dispersion are defined in terms of the absolute deviation. The average absolute deviation, or simply average deviation of a data set is the average of the absolute deviations and is a summary statistic of statistical dispersion or variability. It is also called the mean absolute deviation, but this is easily confused with the median absolute deviation. The average absolute deviation of a set { x 1, x 2, ..., x n} is The choice of measure of central tendency, $m(X)$, has a marked effect on the value of the average deviation. For example, for the data set {2, 2, 3, 4, 14}: The average absolute deviation from the median is less than..   More from Wikipedia

mean deviation : Least absolute deviations (LAD), also known as Least Absolute Errors (LAE), Least Absolute Value (LAV), or the L 1 norm problem, is a mathematical optimization technique similar to the popular least squares technique that attempts to find a function which closely approximates a set of data...   More from Wikipedia

  79-80, mean and standard deviation

  Using the Stats mode on the Casio fx85ES calculator to find the population standard deviation and mean

Question : I know how solve mean and median deviation problems and I don't understand what they really mean. I also don't know why we have to study them.

Answer : standard deviation is a measurement how close your values are to each other. in terms of chemistry, this helps to find out how "precise" your measurements are over several tries. Its always good to know if you are getting consistent data...   More from Yahoo Answers

Question : By hand!! (with the help of a regular calculator!) Find the mean deviation and standard deviation of this set of data: 200, 476, 721, 579, 152, 158

Answer : you find the mean of all those numbers.. so add them all up and then divide them by six.. six because there are six numbers. after that your mean will be 381 to represent the mean you have an x with a line over it _ x = 381 then you take the set and line it up in order 152 158 200 476 579 721 and you subtract the number from the mean so _ x - 152 = 229 and you keep doing that. then you square the number so 229x229 52441 and you do that to every number in the set.. after you find all those numbers find the mean and then find the square root of that and that's your standard deviation you're answer should be about 705.3..   More from Yahoo Answers