We have been given that the standard deviation of a group of 20 scores is 15 and we are asked to find variance.
Since we know variance is square of standard deviation. In order to find out the variance of the given data we have to take the square of 15.
Therefore, our variance is 225.
(4x - 3)(2x - 1) ≥ 0
First, find the zeros:
4x - 3 = 0 2x - 1 = 0
x = x =
Next, plot these points and choose test points on the outside and between the zeros:
←-------0------------
------
------1------→
Lastly, plug in the test points and look for a positive result (since it is greater than 0).
Test Point 0: [4(0) - 3][2(0) - 1] = ( - )( - ) = + THIS WORKS!
Test Point : [4(
) - 3][2(
) - 1] = ( - )( + ) = - <em>This does NOT work</em>
Test Point 1: [4(1) - 3][2(1) - 1] = ( + )( + ) = + THIS WORKS!
Answer: x ≤ or x ≥
Interval Notation: (-∞, ] U [
, ∞)
Graph: ←------
--------→