Q21 of 141 Page 8

If the mean of a frequency distribution is 8.1 and Σfixi = 132 + 5k, Σfi = 20, then k =

If x1, x2, … , xn are observations with frequencies f1, f2, … , fn i.e. x1 occurs f1 times and x2 occurs f2 times and so on, then we have


mean() of observations is given by



Given, mean = 8.1




Putting this values in formula:



⇒ 162 = 132 + 5k


⇒ 5k = 30


⇒ k = 6

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