2/9 of the students in a school are in sixth grade.
1 answer:
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The standard deviation of the data set is 19.3
<h3>How to find the standard deviation of the data set?</h3>The dataset is given as:
82, 94, 105, 68, 57
Calculate the mean using
Mean = Sum/Count
So, we have
Mean = (82 + 94 + 105 + 68 + 57)/5
Evaluate
Mean = 81.2
The standard deviation is then calculated as:
So, we have:
SD = √[(82 - 81.2)^2 + (94 - 81.2)^2 + (105 - 81.2)^2 + (68 - 81.2)^2 + (57 - 81.2)^2)/5 - 1]
This gives:
SD = √[1490.8/4]
So, we have:
SD = 19.3
Hence, the standard deviation of the data set is 19.3
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<h3>Answer: (2, 3, 1)</h3>
This means x = 2, y = 3 and z = 1
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Work Shown:
Double everything in the second equation to get 4x-2y+4z=6
Add this result to the first equation
The first two lines of that expression above shows us adding x+2y-4z=4 to the equation 4x-2y+4z = 6
The x terms add to x+4x = 5x
The y terms add to 2y+(-2y) = 0y
The z terms add to -4z+4z = 0z
The terms on the right hand side add to 4+6 = 10
That's how we end up with the new equation 5x+0y+0z = 10
That becomes 5x = 10 which solves to x = 2 when we divide both sides by 5.
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Use this x value in the third original equation to find z
3x-8z = -2
3(2)-8z = -2
6-8z = -2
-8z = -2-6
-8z = -8
z = -8/(-8)
z = 1
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Use the x and z values we found to find y
x+2y-4z = 4
2+2y-4(1) = 4
2+2y-4 = 4
2y-2 = 4
2y = 4+2
2y = 6
y = 6/2
y = 3
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Overall we get the solutions to be x = 2, y = 3 and z = 1
We can say the solution as an ordered triple is (x,y,z) = (2,3,1)