It is the distance between -14 and 0 on the number line
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.
<h3>
Answer: angle X = 70.5 degrees</h3>
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Work Shown:
Law of Cosines
c^2 = a^2 + b^2 - 2ab*cos(C)
22^2 = 20^2 + 18^2 - 2*20*18*cos(X)
484 = 724 - 720*cos(X)
484 + 720*cos(X) = 724
720*cos(X) = 724 - 484
720*cos(X) = 240
cos(X) = 240/720
cos(X) = 1/3
X = arccos(1/3)
X = 70.528779
X = 70.5
Make sure your calculator is in degree mode.
Step 
<u>Find the irreducible fraction in each ratio</u>
<u>case 1)</u> 
Divide by
boths numerator and denominator

<u>case 2)</u> 
Divide by
boths numerator and denominator

<u>case 3)</u> 
Divide by
boths numerator and denominator

<u>case 4)</u> 
Divide by
boths numerator and denominator

<u>case 5)</u> 
Divide by
boths numerator and denominator

<u>case 6)</u> 
Divide by
boths numerator and denominator

<u>case 7)</u> 
Divide by
boths numerator and denominator

<u>case 8)</u> 
Divide by
boths numerator and denominator

<u>case 9)</u> 
Divide by
boths numerator and denominator

<u>case 10)</u> 
Divide by
boths numerator and denominator

<u>case 11)</u> 
Divide by
boths numerator and denominator

<u>case 12)</u> 
Divide by
boths numerator and denominator

Step 
<u>Sort the ratios into bins</u>
1<u>) First Bin</u>
<u>
</u>



<u>2) Second Bin </u>
<u>
</u>


<u>3) Third Bin</u>



4<u>) Fourth Bin</u>
<u>
</u>



