In a retail market, fruit vendors were selling mangoes kept in packing boxes. These boxes contained varying number of mangoes. The following was the distribution of mangoes according to the number of boxes


Number of mangoes



50 - 52



53 - 55



56 - 58



59 - 61



62 - 64



Number of boxes



15



110



135



115



25



Find the mean number of mangoes kept in a packing box. Which method of finding the mean did you choose?

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


Class Interval



fi



xi



di = x - a



fidi



50-52



15



51



-6



90



53-55



110



54



-3



-330



56-58



135



57



0



0



59-61



115



60



3



345



62-64



25



63



6



150




∑fi = 400





∑fidi = 75



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




= 0.1875


Mean can be calculated as follows:


=


= 0.1875 + 57


= 57.1875


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