Q18 of 33 Page 156

If the mean of a set of observations x1, x2, ...., ...., x10 is 20. Find the mean of x1 + 4, x2 + 8, x3 + 12, .... ...., x10 + 40.

Given,

No of observations, n = 10


Mean,


We know,


Arithmetic mean of x1, x2, x3, …, xn (n observations) is



For given data,



⇒ x1 + x2 + x3 + …+x10 = 200 [1]


Now, to find the mean of


x1+4, x2 + 8, …, xn + 40


No of terms, n = 10


Mean using above formula,







Hence, mean of new data is 42.6


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