AP ICET 2013

Question 145

If the standard deviation of a variable x is 12 then the variance of the variable 2x + 17 is

Solution

Let say

Y = 2X + 17

Taking variance of both sides:

V(Y) = V(2X) + V(17)
V(Y) = 2 V(X) + 0
V(Y) = 2 * 12
V(Y) = 24                              Answer 

V(aX) = a^2 * V(X) .. where a is a constant

V(a) = 0 .. where a is a constant


Create a FREE account and get:

  • Download Maths Shortcuts PDF
  • Get 300+ previous papers with solutions PDF
  • 500+ Online Tests for Free

cracku

Boost your Prep!

Download App