1. Measures of Central Tendency, Variance and Percentage

2. Mean The average of a set of scores Add all scores together, then divide by the total number of scores Ex: 60 76 82 93 +97 408 ÷ 5 = 81.6 (mean)

3. Median The middle number in a set of scores (when listed in numerical order) Ex: 60, 76, 82, 93, 97 If there is an even number of scores, add the middle two together and divide by two (average the middle two numbers) Ex: 60, 76, 82, 84, 93, 97 82+84=166÷2=83 (median)

4. Mode The most frequently occurring number in a set of scores Ex: 60, 76, 82, 82, 93 There can be more than one mode Ex: 60, 76, 76, 82, 93, 97, 97, 98,100

5. Range The measure of points between (and including) the lowest and highest scores Subtract the lowest score in a data set from the highest score and add 1. Ex: 60, 76, 82, 93, 97 97 - 60 37 + 1 38 point range

6. Percentage What percentage (%) of this set of scores are A’s (90-100)? 60, 76, 76, 82, 87, 93, 97, 97, 98, 4 out of 9 scores are A’s #of A’s × 100 ÷ total # of scores 4 × 100 ÷ 9 = 44.44%