QMS 230 Chapter Notes - Chapter 3: Weighted Arithmetic Mean, Central Tendency, Data Set
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Measures of central tendency (use calc: differentiate between the mean, the median, and the mode of data, state the advantages and disadvantages of the three measures. 1 answer: the median indicates the halfway point, the mode is the most frequently occurring value. The mean: the arithmetic mean when all values = the same weight sample mean x population mean (cid:229)=m (cid:229)= x n x. N: the weighted mean when values are weighted different (ex. Marks) (cid:229)= x wx w where m = the population mean; x = the observed values; x = the sample mean; =n the number of observations in the sample; Note: the symbol (cid:229) read sigma and denotes the summation of values. =f (cid:229) the total number of observations in the data set; fm = the sum of the weighted values of the class midpoints. Position number of median in an array = The annual incomes of a sample of middle-management employees at ryerson.