If the data set represents the number of rings each person is wearing, being: 0,2,4,0,2,3,2,8,6, the interquartile range of the data is 2. Being, 4 as the Q1, 3 as the Q2 or median, and 6 as the Q3. Where the formula of getting the interquartile range is IQR= Q1-Q2.
X=9 this is the answer for question 19
The height of the blue spruce was 45.
We find the mean by adding all of the data points and dividing by the number of data points. We will add the unknown value x and change the number we're dividing by to 7:
(160+320+100+110+200+220+x)/7 = 165
(1110+x)/7 = 165
Multiply both sides by 7:
1110 + x = 1155
Subtract 1110 from both sides:
x = 45
Answer: 
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Work Shown:

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Explanation:
The idea is to first get all the y terms to one side. I did this by subtracting 2y from both sides in the third step.
Then factor out y and divide both sides by (8x-2)
Afterward there's the optional steps of simplifying (as shown in the final two steps).