The arithmetic mean of the following frequency distribution is 53. Find the value of k.
Class | 0-20 | 20-40 | 40-60 | 60-80 | 80-100 |
---|---|---|---|---|---|
Frequency | 12 | 15 | 32 | k | 13 |
Class | xi | fi | fixi |
---|---|---|---|
0-20 | 10 | 12 | 120 |
20-40 | 30 | 15 | 450 |
40-60 | 50 | 32 | 1600 |
60-80 | 70 | k | 70k |
80-100 | 90 | 13 | 1170 |
Total | fi= 72 + k |
fixi= 3340 +70k |
Mean