How to calculate the mean from grouped data or frequency table with step by step illustration

1. - Mr Kim

2. Class Frequency, f
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1

3. Class Frequency, f
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
This is a Grouped
Frequency Table

4. To calculate the Mean, the
c.c and fx column must be
added and filled in
Class Frequency, f
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1

5. Class Frequency, f Class centre,
c.c
fx
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
To calculate the Mean, the
c.c and fx column must be
added and filled in

6. Class Frequency, f Class centre,
c.c
fx
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
Start with c.c
column

7. Class Frequency, f Class centre,
c.c
fx
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
0

8. Class Frequency, f Class centre,
c.c
fx
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
90

9. Class Frequency, f Class centre,
c.c
fx
0-9 8
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
2
90 

10. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
5.4
2
90



11. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1

12. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1

13. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
10

14. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
1910

15. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7
20-29 5
30-39 8
40-49 4
50-59 1
2
1910 

16. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5
30-39 8
40-49 4
50-59 1
5.14
2
1910



17. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5
30-39 8
40-49 4
50-59 1

18. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5
30-39 8
40-49 4
50-59 1
2920

19. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5
30-39 8
40-49 4
50-59 1
2
2920

20. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8
40-49 4
50-59 1
5.24
2
2920



21. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8
40-49 4
50-59 1

22. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8
40-49 4
50-59 1
3930
3930

23. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8
40-49 4
50-59 1
2
3930

24. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4
50-59 1
5.34
2
3930



25. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4
50-59 1

26. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4
50-59 1
2
4940

27. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1
5.44
2
4940



28. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1

29. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1
2
5950

30. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5
2
5950
5.54
2
5950



31. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

32. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5
Now, fill in the fx column

33. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

34. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

35. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

36. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

37. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

38. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

39. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

40. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

41. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5
40-49 4 44.5
50-59 1 54.5

42. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5
50-59 1 54.5

43. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5

44. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

45. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

46. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5
Now, calculate the Total fx

47. Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5
Now, calculate the Total fx

48. Total fx =
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

49. Total fx =
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

50. Total fx = 36+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

51. Total fx = 36+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

52. Total fx = 36+101.5+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

53. Total fx = 36+101.5+122.5+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

54. Total fx = 36+101.5+122.5+276+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

55. Total fx = 36+101.5+122.5+276+178+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

56. Total fx = 36+101.5+122.5+276+178+54.5
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

57. Total fx = 36+101.5+122.5+276+178+54.5= 768.5
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

58. Total fx = 768.5
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5
Now, calculate the
Total Frequency

59. Total fx = 768.5
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5
Now, calculate the
Total Frequency

60. Total fx = 768.5
Total f =
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

61. Total fx = 768.5
Total f = 8+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

62. Total fx = 768.5
Total f = 8+7+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

63. Total fx = 768.5
Total f = 8+7+5+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

64. Total fx = 768.5
Total f = 8+7+5+8+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

65. Total fx = 768.5
Total f = 8+7+5+8+4+
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

66. Total fx = 768.5
Total f = 8+7+5+8+4+1
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

67. Total fx = 768.5
Total f = 8+7+5+8+4+1= 33
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5

68. Total fx = 768.5
Total f = 8+7+5+8+4+1= 33
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5
Mean = Total fx ÷ Total f

69. Total fx = 768.5
Total f = 8+7+5+8+4+1= 33
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5
Mean = Total fx ÷ Total f
768.6 ÷

70. Total fx = 768.5
Total f = 8+7+5+8+4+1= 33
Class Frequency, f Class centre,
c.c
fx
0-9 8 4.5 36
10-19 7 14.5 101.5
20-29 5 24.5 122.5
30-39 8 34.5 276
40-49 4 44.5 178
50-59 1 54.5 54.5
Mean = Total fx ÷ Total f
768.6 ÷ 33 = 23.3
Our Final Answer!