Consider the following distribution of daily wages of 50 workers of a factory


Daily wages (in Rs)



100 – 120



120 - 140



140 - 160



160 - 180



180 - 200



Number of workers



12



14



8



6



10



Find the mean daily wages of the workers of the factory by using an appropriate method

The above given data can be represented in the form of table as below:


Class Interval



fi



xi



di = xi - a



fidi



100-120



12



110



-40



-480



120-140



14



130



-20



-280



140-160



8



150



0



0



160-180



6



170



20



120



180-200



10



190



40



400




∑fi = 50





∑fidi = -240



Now, mean of the deviation can be calculated as follows:




= -4.8


Mean can be calculated as follows:


x = d + a


x = -4.8 + 150


x = 145.20


13