Question

The table below shows marks scored by 140 candidates in a test.

Marks	1-10	11-20	21-30	31-40	41-50
No. of candidates	8	23	55	36	18

1. Calculate the mean mark   
2. Calculate the median mark  
3. State the modal class  
4. Draw a frequency polygon for the marks   

Answer 1

Marks	1-10	11-20	21-30	31-40	41-50
No. of candidates	8	23	55	36	18
fx	44	356.5	1402.5	1278	819

Σfx = 3900

1. Mean
   3900  =  27.86
    140 
2. Median mark
   20.5 + (70−31)10
              (   55   )
    =27.59
3. Modal class  21-30
4.