Its 18....................................
Answer:
-1, -7, -13, -19
Step-by-step explanation:
-2(-3)-7 =6-7= -1
-2(0)-7 =0-7= -7
-2(3)-7 =-6-7= -13
-2(6)-7 =-12-7= -19
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.
Answer: The correct option is (B) 24 : 25.
Step-by-step explanation: Given that the perimeter of square region S and the perimeter of rectangular region R are equal and the sides of R are in the ratio 2 : 3.
We are to find the ratio of the area of R to the area of S.
Let 2x, 3x be the sides of rectangle R and y be the side of square S.
Then, according to the given information, we have

Therefore, the ratio of the area of R to the area of S is
![\dfrac{2x\times3x}{y\times y}\\\\\\=\dfrac{5x^2}{y^2}\\\\\\=6\left(\dfrac{x}{y}\right)^2\\\\\\=6\times\left(\dfrac{2}{5}\right)^2~~~~~~~~~~~[\textup{Using equation (i)}]\\\\\\=\dfrac{24}{25}\\\\=24:25.](https://tex.z-dn.net/?f=%5Cdfrac%7B2x%5Ctimes3x%7D%7By%5Ctimes%20y%7D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B5x%5E2%7D%7By%5E2%7D%5C%5C%5C%5C%5C%5C%3D6%5Cleft%28%5Cdfrac%7Bx%7D%7By%7D%5Cright%29%5E2%5C%5C%5C%5C%5C%5C%3D6%5Ctimes%5Cleft%28%5Cdfrac%7B2%7D%7B5%7D%5Cright%29%5E2~~~~~~~~~~~%5B%5Ctextup%7BUsing%20equation%20%28i%29%7D%5D%5C%5C%5C%5C%5C%5C%3D%5Cdfrac%7B24%7D%7B25%7D%5C%5C%5C%5C%3D24%3A25.)
Thus, the required ratio of the area of R to the area of S is 24 : 25.
Option (B) is CORRECT.
Answer:
a=-1
Step-by-step explanation:
-6-5=-11
-11/11=-1