文档介绍：Methods to categorise or arrange data
Stem-and-leaf diagrams/plots/display
Histograms
Cumulative frequency graphs: continous data
Mass
(kg)
Frequency
0--49
50--99
100--149
150--199
200--249
250--299
300--349
12
5
12
17
21
9
1
grouped frequency distributinon 分组频数、频率分布
－ ≤ m <
≤ m <
≤ m <
≤ m <
≤ m <
≤ m <
≤ m <
Frequency
densities
Class
boundaries
Class
width
50
50
50
50
50
50
50
lower class boudaries
upper class boudaries
Time,t
minutes
0≤t<5
5≤t<10
10≤t<15
15≤t<20
20≤t<25
Frequency
10
16
30
22
2
Time,t
minutes
t<5
t<10
t<15
t<20
t<25
Cumulative Frequency
10
26
56
78
80
Cumulative frequency table
points: (5,10) , (10,26), (15,56), ...are plotted.
CUMULATIVE FREQUENCY
A golf club has 200 members. Their ages are shown in the frequency table below. Draw a cumulative frequency curve to represent this information.
Age (a years)
Frequency
0 ≤ a < 10
8
10 ≤ a < 20
26
20 ≤ a < 30
32
30 ≤ a < 40
45
40 ≤ a < 50
37
50 ≤ a < 60
29
60 ≤ a < 70
16
70 ≤ a < 80
7
8
+26
+32
+45
+37
+29
+16
+7
Age (a years)
Cumulative frequency
8
34
66
111
148
177
193
2