Q21 of 108 Page 33

Let x1, x2, ……xn, be n observations. Let yi = axi + b for I = 1, 2, ….., n, where a and b are constant. If the mean of is 48 and their standard deviation is 12, the mean of is 55 and standard deviation of is 15, the values of a and b are

Mean(y) = a.mean(x) + b


Therefore,


55 = a.48 + b


We can see that only first option satisfies this equation. Therefore, a is the correct answer.

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