Q9 of 46 Page 278

The frequency distribution:


where A is a positive integer, has a variance of 160. Determine the value of A.

Given: frequency distribution table, where variance =160


To find: the value of A, where A is a positive number


Let us make a table of the given data and append other columns after calculations



And we know variance is



Substituting values from above table and also given variance=160, we get







⇒ A2=49


⇒ A=7


Hence the value of A is 7.


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