The following table gives the number of boys of a particular age in a class of 40 students. Calculate the mean age of the students.


Age (in year):



15



16



17



18



19



20



No. of students:



3



8



10



10



5



4



Age (x)



No. of students (y)



yx



15



3



45



16



8



128



17



10



170



18



10



180



19



5



95



20



4



80




N = 40



yx = 698



Mean =


= = 17.45


Therefore, mean age is 17.45 years.


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