Q14 of 145 Page 407

What is the cumulative frequency of the modal class of the following distribution?























Class



3 - 6



6 - 9



9 - 12



12 - 15



15 - 18



18 - 21



21 - 24



Frequency



7



13



10



23



4



21



16


Here, the maximum class frequency is 23.

The class corresponding to this frequency is the modal class. ⇒ modal class = 12 - 15


Lets form a table.

















































CLASS



FREQUENCY(fi)



Cf



3 - 6



7



7



6 - 9



13



7 + 13 = 20



9 - 12



10



20 + 10 = 30



12 - 15



23



30 + 23 = 53



15 - 18



4



53 + 4 = 57



18 - 21



21



57 + 21 = 78



21 - 24



16



78 + 16 = 94



TOTAL



94




Since, modal class = 12 - 15, the corresponding cumulative frequency is 53.


More from this chapter

All 145 →
12

The median of 19 observations is 30. Two more observations are made and the values of these are 8 and 32. Find the median of the 21 observations taken together.

 13

If the median of and , where x > 0, is 8, find the value of x.

 15

Find the mode of the given data:

















Class interval



0 - 20



20 - 40



40 - 60



60 - 80



Frequency



15



6



18



10


 16

The following are the ages of 300 patients getting medical treatment in a hospital on a particular day:





















Age (in years)



10 - 20



20 - 30



30 - 40



40 - 50



50 - 60



60 - 70



Number of patients



60



42



55



70



53



20



Form a 'less than type' cumulative frequency distribution.