Rodney Buckmire
MAT102 – Module 2 – Case
Professor Choi
Part 1
1.
To get the standard deviation of these numbers I first calculated the mean by added all the
numbers together (298, 125, 411, 157, 231, 213, 304, 272) and divided it by 8. I then took
the mean(251.375) and calculated the deviance by subtracting the mean from each one of
the numbers in the set. Then I squared each of the individual deviations, added those
sums together, and divided the number I got from that sum by one less than the data set,
which is 7 (8230.55357). Then the last step is calculating the square root, which is the
ending result (90.7224)
So the standard deviation of this set of numbers is 90.7224.
2.
Set 1:
Range : maximum  minimum = 154110= 44
Number of cases 8
To find the mean, add all of the observations and divide by 8
Mean 125
Squared deviations
(120125)^2 = (5)^2 = 25
(123125)^2 = (2)^2 = 4
(153125)^2 = (28)^2 = 784
(128125)^2 = (3)^2 = 9
(124125)^2=
(1)^2= 1
(118125)^2 = (7)^2 = 49
(154125)^2 = (29)^2 = 841
(110125)^2 = (15)^2 = 225
Add the squared deviations and divide by 8
Variance = 1938/7
Variance = 276.857
Standard deviation
= sqrt(variance) = 16.639
Set 2:
Range : 156110 =46
Number of cases 8
To find the mean, add all of the observations and divide by 8
Mean 131.75
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 Fall '11
 Choi
 Math, Standard Deviation

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