If the standard deviation of x1,x2,…,xn is 3.5, then the standard deviation of −2x1−3, −2x2−3,….. …,−2xn−3 is
-7
-4
7
1.75
We know that if di=xi−A1h . then σx=|h|σd
In this case −2xi−3=∣xi+3/2−1/2 so h=←−1/2. Thus σd=
1|h|σx=-2×3.5=-7.