Key Terms Measures of central tendency (averages): Mean Median Mode
Mean Most common type of average Calculated by adding all of the values up and then dividing the total by the number of values M is typically the symbol for mean, n is typically the symbol for sample size
Mean To calculate the mean, you add 2150 to 1534 to 3564 and divide the sum by 3 (n = 3) The mean is 2416
Weighted Mean When you have multiple occurrences of the same value in a data set Calculated as (value x frequency)/total frequency
Weighted Mean To calculate the weighted mean, divide (total value x frequency) by (total frequency) The weighted mean is 89.67
Median The median is simple the middle value when all values are arranged from highest to lowest In the data set, half (50%) of the values should fall above the median and half should fall below When there are an even number of values, the median is the mean of the two middlemost values
Median For odd-numbered data sets, select the middle value For even number data sets take the mean of the two middle values The median for the first data set is $42537. The median for the second data set is $42447.
Mean VS. Median Q: Why use the median as a measure of central tendency? A: Median is not sensitive to extreme scores (outliers)
Mean VS. Median The mean for this data set is $50056. The median is $42537.
Mode Mode is, very simply, the most frequently occur piece of data in the set In this data set, the mode is Brown hair