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Lab 227 08/24/10
Chapter 1
Statistical notation
•
The summation notation is the Greek letter
sigma
:
∑
.
•
Order of operations:
1.
Any calculation within parentheses.
2.
Squaring (or raising to other exponents)
3.
Multiplying or dividing.
4.
Summation using the ∑
5.
Any other addition or subtraction
Class example A
1.
calculate ∑X, ∑X
2
, (∑X)
2
on the following scores: 4, 2, 8, 3.
X
X
2
4
16
2
4
8
64
3
9
∑X = 17
∑X
2
= 93
(∑X)
2
= 289
2.
On the same scores, calculate ∑(X1), ∑(X1)
2
X
X
2
(X1)
(X1)
2
4
16
3
9
2
4
1
1
8
64
7
49
3
9
2
4
∑X = 17
∑X
2
= 93
∑(X1)= 13
∑(X1)
2
= 63
(∑X)
2
= 289
Class example B
In some cases we may have more than one score for each person.
Person
X
Y
XY
A
4
5
20
B
2
3
6
C
8
4
32
D
3
2
6
∑X = 17
∑Y = 14
∑X Y= 64
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View Full DocumentClass example C
Calculate ∑X
2
, (∑X)
2
, ∑(X3), ∑(X3)
2
, and ∑(X
2
–3)on the following scores: 4, 0, 0, 8
X
X
2
(X3)
(X3)
2
(X
2
–3)
4
16
1
1
13
0
0
3
9
3
0
0
3
9
3
8
64
5
25
61
∑X = 12
∑X
2
= 80
∑(X3)= 0
∑(X3)
2
= 44
∑(X
2
–3)=68
(∑X)
2
= 144
Class example D
Calculate ∑X
2
, (∑X)
2
, ∑(X+3), and ∑(X+3)
2
on the following scores: 5, 1, 0, 3, 4
X
X
2
X+3
(X+3)
2
5
25
8
64
1
1
2
4
0
0
3
9
3
9
0
0
4
16
7
49
∑X = 5
∑X
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 Fall '10
 Fairchild

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