CHEM 445
Statistics and Sig Figs Key
Problem 1: Simple Statistics
Given the following replicate measurements:
10.23 7.59 7.46 7.41 7.44 8.19 7.27 6.57
9.34 7.28 8.20 7.90 8.25 5.88 8.67 9.50
7.16 7.41 5.15 7.63 7.30 10.24 8.10 8.93
7.88 8.87 9.35 7.42 5.12 9.41 10.95 8.24
8.39 6.09 9.74 8.49 8.16 7.96 7.53 8.87
6.32 7.90 6.85 7.30 7.02 9.87 8.30 7.45
10.67 8.78 10.52 6.15 8.65 7.83 7.69 7.08
7.36 7.78 6.46 7.49 5.70 5.30 8.49 12.60
7.48 8.00 6.56 6.34 6.03 5.78 9.24 6.23
6.63 10.16 9.43 11.69 10.08 9.39 6.08 8.66
4.98 4.95 5.80 8.27 9.54 10.05 8.86 9.26
7.15 6.90 5.56 5.79 7.47 6.52 7.13 6.80
9.60 5.66 6.83 11.22 6.04 7.04 9.09 7.72
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Calculate the mean or average
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Calculate the median
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Calculate the standard deviation
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Calculate the relative standard deviation (RSD) in percent.
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Calculate the relative standard deviation (RSD) in parts per thousand.
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Calculate the range or spread of the data
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Calculate the standard error of the mean
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CHEM 445 - F2016
Dr. Overway
________
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Page 1 of 2
533568354
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Instrumental Analysis
www.bridgewater.edu/~koverway
CHEM 445
Statistics and Sig Figs Key
Problem 2: Significant Figures
Properly format the following numbers. State which ones you would consider zero.
conc.
(mg/L)
std. dev.
(mg/L)
43.375
46.84606
27.125
0.158644
28.25
16.80986
73.25
8.110756
46.375
12.61448
-5.875
16.52217
178
118.3611
22.75
9.942693
conc. (mg/L)
std. dev. (mg/L) Consider this zero?
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Problem 4: Pooled Standard Deviation
Given the following data sets that were measured on the same instrument:
set
1) 2.23, -0.57, 2.24, 2.02, 2.05
2) 3.65, 2.91, 1.62
3) 3.1, 2.86, 4.01, 0
4) 3.54, 2.21, 4.1, 1.44, 3.31
5) 2.7, 3.15, 4.62

Calculate the standard deviation for set 1
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
Calculate the standard deviation for set 2
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Calculate the standard deviation for set 3
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
Calculate the standard deviation for set 4
________
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Calculate the standard deviation for set 5
________

Calculate the pooled standard deviation for all of the sets
CHEM 445 - F2016
Dr. Overway
________
Page 2 of 2
533568354
Instrumental Analysis
www.bridgewater.edu/~koverway