Question

2. Calculate arithmetic mean of the following frequency distribution:
Class
less than 10
10-20
20-30
30-40
40-50
50-60
more than 60
Frequency
5
12
18
22
6
4
3​

Answer 1

Step-by-step explanation:

10-20. 5 4.5 * 22.5

20-30. 12 6 * 72

30-40. 18 9 * 162

40-50. 22 11 * 242

50-60. 6 3 * 18

60-70. 4 2 * 8

70-80 3 2.5 * 7

5+12+18+22+6+4+3 =70

22.5+72+162+ 242+18+8+7=539.5

mean =539.5÷70=7.70714