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Statistics: Exam 1
A)
Summation

∑
=
Add
 Start with
i
value, stop with top #, fill in as
x
and add up
28
)
(
4
)
(
1
=
∑
=
stop
start
i
x
∑
=
=
4
3
18
i
x
Constant (c) =
2
48
10
16
12
)
10
2
(
)
8
2
(
)
6
2
(
4
2
=
+
+
=
⋅
+
⋅
+
⋅
=
∑
=
i
cx
=
∑
=
3
1
2
i
y
cx
756
7
36
3
7
6
3
192
4
16
3
4
4
3
12
1
4
3
1
2
3
2
2
2
=
⋅
⋅
=
⋅
⋅
=
⋅
⋅
=
⋅
⋅
=
⋅
⋅
=
⋅
⋅
= 12+192+756 = 960
c=3
x
4
6
8
10
6
x
y
2
1
4
4
6
7
8
8
11
9
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View Full DocumentB)
Constructing Frequency Distribution Tables
1)
# of class intervals
: given
EX: 6 CI
2)
Determine size of CI
: (round if decimal)
Highest value – lowest value
# of class intervals
EX:
9529
= 11
size=11
6
3)
Determine lowest CI
:
a) must contain lowest score
b) lowest score in LCI must be evenly divisible by the size of CI
EX:
2232
4)
Find other intervals
: add by size, remember to include # when
counting
EX:
2232, 3343, 4454, 5565, 6676, 7787, 8898
5)
Make table, find
:
a) Frequency (f): count how many numbers fall in each interval
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 Spring '08
 johnson

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