Question

Exercise 1.
1. Calculate arithmetic mean in the following table by direct and short method :
Size
30 29 28 27 26 25 24 23 22 21
Frequency 2 4 5 3 2 7 1 4 5 7​

Answer 1

Answer:

Explanation:

direct method :-

xi       fi       fixi

30      2      60

29      4       116

28       5      140

27        3      81

26       2       52

25       7       175

24         1       24

23         4       92

22        5        110

21          7​        147

           -----      -------

            40        997

mean = fixi / fi

          = 997 / 40

          = 24.925

Answer 2

Answer:
24.925
Explanation:

Direct method:-

xi Fi Fixi
30 2 60
29 4. 112
28. 5 140
27 3. 81
26 2 52
25. 7. 175
24 1. 24
23 4 92
22 5. 110
21 7. 147

Mean=fixi/fi
=997/40
=24.925