1. Mean, Median, Mode & Range class-VII (demo 2) By G.D.GUPTA TGT MATHEMATICS K. V. ITARANA

2. Copyright © 2000 by Monica Yuskaitis Data- A data is a collection of numbers gathered to give some information. e.g. marks obtained by 10 students in a test of class VIII, out of 20 as follows: 15,12,14,16,07,16,18,13,05,20

3. Copyright © 2000 by Monica Yuskaitis Different Names Mean Means Average Arithmetic Mean

4. Copyright © 2000 by Monica Yuskaitis General meaning of mean- 2, 5, 2, 1, 5

5. Copyright © 2000 by Monica Yuskaitis 2, 5, 2, 1, 5

6. Copyright © 2000 by Monica Yuskaitis 2, 5, 2, 1, 5 mean = 3

7. Copyright © 2000 by Monica Yuskaitis MeanMean – The mean of a group of observation is 2, 5, 2, 1, 5 Mean = 3 ?

8. Copyright © 2000 by Monica Yuskaitis How to Find the Mean of a Group of Numbers Step 1 – Add all the numbers. 8, 10, 12, 18, 22, 26 8+10+12+18+22+26 = 96

9. Copyright © 2000 by Monica Yuskaitis Step 2 – Divide the sum by the number of observation. 8, 10, 12, 18, 22, 26 8+10+12+18+22+26 = 96 How many observation are there?

10. Copyright © 2000 by Monica Yuskaitis How to Find the Mean of a Group of Numbers Step 2 – Divide the sum by the number of observation. 6)6) 96 sum 1 6 36 6 63 # no. of observation

11. Copyright © 2000 by Monica Yuskaitis sum of all observations Mean = total no. of observations

12. Copyright © 2000 by Monica Yuskaitis The mean or average of these numbers is 16. 8, 10, 12, 18, 22, 26

13. Copyright © 2000 by Monica Yuskaitis What is the mean of these numbers? 2, 9, 14, 27 ?

14. Copyright © 2000 by Monica Yuskaitis Definition Median is the value of the Middle Middle observation.

15. Copyright © 2000 by Monica Yuskaitis Definition MedianMedian – the value of middle observation in a group of numbers. 1, 3, 7, 10, 13 Median = 7

16. Copyright © 2000 by Monica Yuskaitis How to Find the Median in a Group of Numbers Step 1 – Arrange the observation in ascending or descending order. 21, 18, 24, 19, 27 18, 19, 21, 24, 27

17. Copyright © 2000 by Monica Yuskaitis How to Find the Median in a Group of Numbers Step 2 – Find the middle observation. 21, 18, 24, 19, 27 18, 19, 21, 24, 27

18. Copyright © 2000 by Monica Yuskaitis 18, 19, 21, 24, 27 This is your median number.

19. Copyright © 2000 by Monica Yuskaitis How to Find the Median in a Group of Numbers Step 3 – If there are two middle observation, find the mean of these two numbers. 18, 19, 21, 25, 27, 28

20. Copyright © 2000 by Monica Yuskaitis How to Find the Median in a Group of Numbers Step 3 – If there are two middle observation, find the median of these two numbers. 21+ 25 = 46 2)2) 23 median

21. Copyright © 2000 by Monica Yuskaitis What is the median of these numbers? 29, 8, 4, 11, 19 ?

22. Copyright © 2000 by Monica Yuskaitis What is the median of these numbers? 31, 7, 2, 12, 14, 19 ?

23. Copyright © 2000 by Monica Yuskaitis Definition Mode is the most Popular

24. Copyright © 2000 by Monica Yuskaitis Definition Mode Mode – the most popular or that which is most required. Baseball caps are a mode today.

25. Copyright © 2000 by Monica Yuskaitis Definition ModeMode – the number that appears most frequently in a set of numbers. 1, 3, 7, 10, 13 Mode = 1

26. Copyright © 2000 by Monica Yuskaitis How to Find the Mode in a Group of Numbers Step 1 – Arrange the numbers in ascending or descending order. 21, 18, 24, 19, 18 18, 19, 21, 24

27. Copyright © 2000 by Monica Yuskaitis How to Find the Mode in a Group of Numbers Step 2 – Find the number that is repeated the most. 21, 18, 24, 19, 18 18, 18, 19, 21, 24

28. Copyright © 2000 by Monica Yuskaitis Which number is the mode? 29, 8, 4, 8, 19 8 4, 8, 19, 29

29. Copyright © 2000 by Monica Yuskaitis Which number is the mode? 1, 2, 2, 9, 9, 4, 9, 10 9 1, 2, 4, 9, 10

30. Copyright © 2000 by Monica Yuskaitis Which number is the mode? 22, 21, 31, 31, 21, 32, 21, 22, 31, 32 21and 31 are the mode of given data.

31. Copyright © 2000 by Monica Yuskaitis Definition RangeRange – the difference between the greatest and the least value in a group of numbers. 1, 3, 7, 10, 13 Range = 12

32. Copyright © 2000 by Monica Yuskaitis How to Find the Range in a Group of Numbers Step 1 – Arrange the numbers in order from least to greatest. 21, 18, 24, 19, 27 18, 19, 21, 24, 27

33. Copyright © 2000 by Monica Yuskaitis How to Find the Range in a Group of Numbers Step 2 – Find the lowest and highest numbers. 21, 18, 24, 19, 27 18, 19, 21, 24, 27

34. Copyright © 2000 by Monica Yuskaitis How to Find the Range in a Group of Numbers Step 3 – Find the difference between these 2 numbers. 18, 19, 21, 24, 27 27 – 18 = 9 The range is 9

35. Copyright © 2000 by Monica Yuskaitis What is the range? 22, 21, 27, 31, 21, 32 ?

36. Copyright © 2000 by Monica Yuskaitis