Example 1. The weights of a random sample of 40 female college students:
Data
weights
135 117 137 135 133 145 129 157 113 134
144 141 132 138 133 134 132 135 152 141
140 119 138 136 156 141 116 131 138 128
120 148 130 140 121 137 121 145 145 125
|
| Stem-and leaf plot | Descriptive statistics |
|---|---|
Stem-and-leaf of weights N = 40
Leaf Unit = 1.0
1 11 3
4 11 679
7 12 011
10 12 589
18 13 01223344
(9) 13 555677888
13 14 001114
7 14 5558
3 15 2
2 15 67
|
N Mean Median StDev SE Mean 40 134.80 135.00 10.44 1.65 Minimum Maximum Q1 Q3 113.00 157.00 129.25 141.00 |
| Histogram | Boxplot |
|---|---|
|
|
The "shape" of the data is called "symmetric" or "bell-shaped."
Example 2. A random sample of 26 grades on an easy statistics exam.
Data
easyexam
100 100 99 98 97 96 95 95 95 94
93 93 92 92 91 90 90 90 89 84
80 75 68 65 50 45
|
| Stem-and leaf plot | Descriptive statistics |
|---|---|
Stem-and-leaf of easyexam N = 26
Leaf Unit = 1.0
1 4 5
2 5 0
2 5
2 6
4 6 58
4 7
5 7 5
7 8 04
8 8 9
(9) 9 000122334
9 9 5556789
2 10 00
|
N Mean Median StDev SE Mean 26 86.77 92.00 14.66 2.87 Minimum Maximum Q1 Q3 45.00 100.00 83.00 95.25 |
| Histogram | Boxplot |
|---|---|
 |
 |
The "shape" of the data is called "skewed to the left."
Example 3. The lifetimes of a random sample of 39 Energizer bunnies.
Data
lifetime
0.2 3.6 3.1 0.9 0.7 7.8 1.4 0.4 3.1 3.4
5.3 3.2 0.3 3.1 6.0 2.8 5.6 0.2 1.4 0.9
2.4 0.8 1.8 1.0 2.9 0.5 0.9 3.2 1.3 11.1
0.8 1.8 1.4 0.2 1.0 1.1 1.6 0.7 3.2
|
| Stem-and leaf plot | Descriptive statistics |
|---|---|
Stem-and-leaf of lifetime N = 39
Leaf Unit = 0.10
13 0 2223457788999
(10) 1 0013444688
16 2 489
13 3 11122246
5 4
5 5 36
3 6 0
2 7 8
1 8
1 9
1 10
1 11 1
|
N Mean Median StDev SE Mean 39 2.336 1.400 2.282 0.365 Minimum Maximum Q1 Q3 0.200 11.100 0.800 3.200 |
| Histogram | Boxplot |
|---|---|
 |
 |
The "shape" of the data is called "skewed to the right."