7.2 - Range and Median

Focus: Given some data, calculate the Range of the data and calculate the Median Score. The following scores came from a Grade 7 Social exam: 65 89 51 82 57 98 48 59 78 78 91 77 65 77 85 87 77 90 77 91 100 70 88 50 60 83 76 Organize these into a stem and leaf chart: Stem Leaf 4 8 5 0179 6 055 7 06777788 8 235789 9 0118 10 0 Range The Range in the data (or test scores) is the difference between the Highest value in the data and the Lowest score in the data. In our data, the Range is...100 - 48...or 52 Median The Median of a data set (or test scores) is the middle number when the data are arranged in order. In our data, there are 27 scores, so the middle score is the 14th value...77 is the Median If there was an even number of values, we would take the mean (or average) of the two middle scores to determine the median... Example: 3, 5, 9, 13, 17, 18 In this set of data, 9 and 13 are the "middle numbers" so we take their mean to determine the median... (9 + 13) divided by 2 = 11 Practice page 264-65 #1-4