Question

Find out mean and median of the following data,Marks,0-10,10-20,20-30,30-40,40-50,50-60,60-70,70,80 and students-5,10,20,40,30,20,10,4

Answer 1

Answer:

For calculating the Mean and Median of the following above given data, let us first calculate certain information from the table in figure below:

N = ∑f = 139  

∴ Mean = [∑(f *m)] / N = 5475 / 139 = 39.38

Now, for Median, we have

Median = L + [(N/2 – c) / f] * i

Here, L = lower limit of the median class

c = 35 = previous cumulative frequency

f = 40 = frequency of the particular median class

i = 10 = interval of marks

∴ Median = L+[(N/2 – c)/f] * i = 30+[(69.5-35)/40]*10 = 38.625

Figure below consists the calculated values, required for mean and median, in a tabular form: