Stat 101: Lecture 7
Size of Diamonds
Size of Diamonds (carats)
Frequency
15
10
5
0
0.1
0.2
0.3
0.4
Size (carats)
1
Five Number Summary
Maximum
0.35
Q3
0.25
Median
0.18
Q3
0.16
Minimum
0.12
2
Box Plots
• Establish an axis with a scale.
• Draw a box that extends from the
first to the third quartile.
• Draw a line from the first quartile
to the minimum and another line
from the third quartile to the
maximum.
3
Stat 101: Lecture 7
Box Plot
0.10
0.15
0.20
0.25
0.30
0.35
Carats
4
Outlier Box Plots
• Establishes boundaries on what
are “usual” values based on the
width of the box.
• Values outside the boundaries
are flagged as potential outliers.
5
Contents of Regular Cola
360
365
370
375
380
W eight (gram s)
6
Stat 101: Lecture 7
Comparing Distributions
• How do the distributions
compare in terms of
–Shape?
–Center?
–Spread?
7
Workout Times
• Who? ISU students.
• What? Time spent working out
(minutes), Gender
– When? 1998.
– Where? Second floor of Leid Recreation
facility.
– How? The time was noted when a student
arrived at the 2nd floor workout area and
when that student left.
8
Workout Times: Men
5
3
Count
4
2
1
30
40
50
60
70
80
90
100
9
Stat 101: Lecture 7
Workout Times: Women
5
3
Count
4
2
1
30
40
50
60
70
80
90
100
10
Work Out Times (min)
Group
Mean
Std
Dev
Median
IQR
Men
55.9
13.53
54
16
Women
69.2
13.79
69
15
11
Comparing Groups
• Regular
– Min: 362 g
– QL: 366.5 g
– Med: 368.5 g
– QU: 370 g
– Max: 378 g
• Diet
– Min: 349 g
– QL: 352.5 g
– Med: 354 g
– QU: 355 g
– Max: 357 g
12
Stat 101: Lecture 7
Comparing Groups
Type of Cola
R
D
3 45
350
355
36 0
365
370
37 5
380
385
W eight (gram s)
13
Comparing Groups
• Compare shape.
• Compare center.
• Compare spread.
• Compare outliers, if there are
any.
14
Comparing Groups
Oneway Analysis of Weight By Type of Cola
380
375
Weight
370
365
360
355
350
345
D
R
Type of Cola
15