1. Central Tendency Mean – the average value of a data set. Add all the items in a data set then divide by the number of items in the data set.

2. Central Tendency

5. Mean – the average value of a data set. Add all the items in a data set then divide by the number of items in the data set. EXAMPLE # 2 : Find the mean of the following data set 12, 10, 14, 19, 17, 11, 12, 16, 15

6. Central Tendency

7. Median – the value in the data set that is “in the middle”. It has half of the data in the set above it and half of the data in the set below it. Order the data in the set from smallest to largest. If there is an odd number of data items, then the middle data item is the median. If there is an even number of data items, then the mean of the middle two data items is the median.

8. Central Tendency Median – the value in the data set that is “in the middle”. It has half of the data in the set above it and half of the data in the set below it. Order the data in the set from smallest to largest. If there is an odd number of data items, then the middle data item is the median. If there is an even number of data items, then the mean of the middle two data items is the median. EXAMPLE : Find the median of the following data set 72, 85, 81, 79, 93, 76, 86

9. Central Tendency Median – the value in the data set that is “in the middle”. It has half of the data in the set above it and half of the data in the set below it. Order the data in the set from smallest to largest. If there is an odd number of data items, then the middle data item is the median. If there is an even number of data items, then the mean of the middle two data items is the median. EXAMPLE : Find the median of the following data set 72, 85, 81, 79, 93, 76, 86 Order from small to big : 72, 76, 79, 81, 85, 86, 93

10. Central Tendency Median – the value in the data set that is “in the middle”. It has half of the data in the set above it and half of the data in the set below it. Order the data in the set from smallest to largest. If there is an odd number of data items, then the middle data item is the median. If there is an even number of data items, then the mean of the middle two data items is the median. EXAMPLE : Find the median of the following data set 72, 85, 81, 79, 93, 76, 86 Order from small to big : 72, 76, 79, 81, 85, 86, 93 There are an odd # of items so the middle one is the median

11. Central Tendency Median – the value in the data set that is “in the middle”. It has half of the data in the set above it and half of the data in the set below it. Order the data in the set from smallest to largest. If there is an odd number of data items, then the middle data item is the median. If there is an even number of data items, then the mean of the middle two data items is the median. EXAMPLE #2 : Find the median of the following data set 5, 8, 3, 2, 4, 6

12. Central Tendency Median – the value in the data set that is “in the middle”. It has half of the data in the set above it and half of the data in the set below it. Order the data in the set from smallest to largest. If there is an odd number of data items, then the middle data item is the median. If there is an even number of data items, then the mean of the middle two data items is the median. EXAMPLE #2 : Find the median of the following data set 5, 8, 3, 2, 4, 6 Order from small to big2, 3, 4, 5, 6, 8

13. Central Tendency

14. Mode – the data item that appears most often in a data set

15. Central Tendency Mode – the data item that appears most often in a data set EXAMPLE : Find the mode of the given data set 21, 18, 20, 21, 27, 24, 21, 25, 28

16. Central Tendency Mode – the data item that appears most often in a data set EXAMPLE : Find the mode of the given data set 21, 18, 20, 21, 27, 24, 21, 25, 28 Mode = 21 As you can see, 21 appears three times in the data set

17. Central Tendency Range – the difference between the largest and smallest data item in the data set

18. Central Tendency Range – the difference between the largest and smallest data item in the data set EXAMPLE : Find the range of the given data set 65, 68, 72, 73, 81, 82, 85, 91, 92

19. Central Tendency