Download DESCRIPTIVE STATISTICS

Descriptive Statistics
Number
pictures of data
Number distributions
Measures of central tendency
Measures of variation
Z scores
Percent and percentile
Number Pictures
Frequency
graph
Bar graph or histogram
Frequency polygon
Frequency curve
Frequency Graph
6
5
4
3
2
1
0
0
1
2
3
4
5
6
7
8
9
10
Bar Graph/Histogram
6
5
4
3
2
1
0
0
1
2
3
4
5
6
7
8
9
10
Frequency Polygon
6
5
4
3
2
1
0
0
1
2
3
4
5
6
7
8
9
10
Frequency Curve
7
6
5
4
3
2
1
0
0
1
2
3
4
5
6
7
8
9
10
Number Distributions
Normal
curve
Negative skewed curve
Positive skewed curve
Normal Distribution
-3 -2 -1 0 +1 +2 +3
Z
Normal Distribution
34.13%
34.13%
13.59%
2.27%
-3
-2
13.59%
2.27%
-1
0
+1
+2
+3
Z
Stanford-Binet
34.13%
13.59%
2.27%
52
34.13%
13.59%
2.27%
68
84 100 116 132
IQ TEST DISTRIBUTION
148
Negatively Skewed
Distribution
Mode
Mean
Median
Positively Skewed
Distribution
Mode
Median
Mean
Central Tendency
Mode
Median
Mean

x
n
x
Variation
Range
Variance
Standard
R X  X
H
L
S
2


 x  x
2
n 1
deviation
S

 x  x
n 1
2
Z Scores
Single
score description
Relation of raw score to mean
accounting for variation
Z = sum of (x  x)/ s
Standard score
Deviation score in standard
deviation units
Percent
Proportion
of a whole
Quantity - # units in proportion to 100
%= (F)n / (t)n * 100
Percentile
A number’s
position in a group of
numbers
Percentage of numbers below the
number
Median = 50th percentile