Answer:
<em>B. </em>
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Step-by-step explanation:
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.
Ok, so you automatically know that you are subtracting 6 from 10 to get 4. So, in order to figure out how it is 1/3 of that number, it is going to be multiplied by 3, getting 18. So, the number would be 18.
Answer:

Step-by-step explanation:
We need to find ration numbers between -1 and 1.
Multiplying and dividing both -1 and 1 by 2.

and 
Now, the rational number between -2/2 and 2/2 is
.
185582/25 i got this using the power of a calculator.