Scores  Frequency  Cumulative frequency (cf) 
















Class intervals  Frequency  Less than type Cumulative frequency  Greater than type Cumulative frequency 


9  50 


9 + 14 = 23  50  9 = 41 


9 + 14 + 8 = 31  50  9 14 = 27 


9 + 14 + 8 + 10 = 41  50  9 14  8 = 19 


9 + 14 + 8 + 10 + 9 = 50  50  9 14  8  10 = 9 

Classes  10  20  20  30  30  40  40  50  50  60  60  70  70  80 
Frequency  4  8  10  12  10  4  2 
Classes  Frequency (fi)  Cumulative frequency 





















Total  N = Σ fi = 50 