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Z Scores and (maybe) Outliers |
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Assign. #1 |
Basic Stat |
Internet Section 881 |
Z-Scores (also called "Standard Scores") |
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Do this assignment in the ORIGINAL ORDER, not by size. Answer questions below. |
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Note: the data you enter and its order are to be used in all the assignments. |
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Order no. |
Round all calculations to TWO PLACES AFTER THE DECIMAL POINT. |
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Your scores |
- Mean |
"=DEVIATIONs |
devs. squared |
Zscores = each DEV/Stan. Dev. |
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1 |
5 |
6.50 |
-1.50 |
2.25 |
-0.43 |
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2 |
7 |
6.50 |
0.50 |
0.25 |
0.14 |
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3 |
8 |
6.50 |
1.50 |
2.25 |
0.43 |
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4 |
6 |
6.50 |
-0.50 |
0.25 |
-0.14 |
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5 |
11 |
6.50 |
4.50 |
20.25 |
1.30 |
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6 |
4 |
6.50 |
-2.50 |
6.25 |
-0.72 |
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7 |
3 |
6.50 |
-3.50 |
12.25 |
-1.01 |
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8 |
10 |
6.50 |
3.50 |
12.25 |
1.01 |
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9 |
1 |
6.50 |
-5.50 |
30.25 |
-1.59 |
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10 |
12 |
6.50 |
5.50 |
30.25 |
1.59 |
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11 |
9 |
6.50 |
2.50 |
6.25 |
0.72 |
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12 |
2 |
6.50 |
-4.50 |
20.25 |
-1.30 |
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Excel can caluclate colored figures right and below |
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Sum of devs. squared = |
143 |
"sum of squares" |
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Mean (average) dev. sq. = |
11.92 |
"variance" |
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Square root of Mean (average) dev. sq. = |
3.45 |
"STANDARD DEVIATION" |
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N = |
12 |
N |
"= number of scores: how many are there? |
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MEAN = |
6.50 |
Mean |
"= usual average, sum of scores divided by N |
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Median = |
6.50 |
Median |
"= mid score (or average of 2 mid scores when N is even) after all are in order |
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Mode(s) = |
no mode |
Mode(s) |
"=most frequently occuring; don't list more than 2 scores TIED FOR MOST |
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What score is most divergent from the mean? |
Your answer here |
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What is the Z score associated with the most divergent score? |
Your answer |
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(Define outlier as "score 2 or more standard deviations from mean".) |
Is your set of scores a single set or are there one or more outliers? |
Answer: "single set" or "outlier(s)" |
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This assignment creates Z scores, to evaluate the dispersion of your scores. |
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