Following data relates to daily wages of persons working in a factory…

The correct answer is Option 4: 38.33

Daily Wages (Rs)	Number of Workers	Cumulative Frequency (c.f)
20-30	25	25
30-40	12	37
40-50	15	52
50-60	13	65
60-70	5	70
	N = 70

In case of continuous series we have to locate the median class where N/2th item lies.

In the above question median class is the value of (N/2)th item (i.e.70/2) = 35th item of the series, which lies in 30–40 class interval.

The median can then be obtained as follows: Median =L + [(N/2- c.f)/f] * h

Where, L = lower limit of the median class

c.f. = cumulative frequency of the class preceding the median class,

f = frequency of the median class,

h = magnitude of the median class interval.

Putting the values in the formula,

Median = 30 + [(35-25)/12] * (10)

           = 30 + (10*10)/12

           = 38.33