Exercise 2
: Table 2.3 contains the daily high temperatures at the Cleveland National Weather Service forecast off for the
month of May, 2015. Use the data to construct a frequency distribution with 6 classes.
Table 2.2
66
89
79
62
85
72
88
73
72
83
79
86
82
82
60
81
88
80
82
69
65
69
85
70
51
51
83
82
64
59
77

Module 1: Organizing Data – The Frequency Distribution
Here are three exercises for you to work through. My recommendation is that you attempt to do each of these without
looking at my solution.
Then, after completing it, look at the solution. Hopefully after you do all three, you’ll have a very
good handle on how to convert raw data to a frequency distribution.
Exercise 3
: Table 2.4 is a partially completed frequency distribution for a data set. Complete it.
Table 2.4
Class Interval
F
0 to under 5
6
5 to under 10
8
10 to under 15
17
15 to under 20
23
20 to under 25
18
25 to under 30
10
30 to under 35
4

Module 1: Organizing Data – The Frequency Distribution
Exercise 1 Solution
Table 2.2
14
34
42
35
33
9
23
30
22
27
8
9
20
7
14
20
16
15
19
29
18
47
44
21
19
6
10
28
32
43

Module 1: Organizing Data – The Frequency Distribution
Exercise 1 Solution
Step 1: Find the range. Sort data into ascending order. 47-6 =
41
Step 2: Decide how many classes the data will be grouped into.
7
(Given)
Step 3: Determine the width (w) of the class intervals.
W = Class Width (W) =
= = 5.8751
Will round up to
6
•
6
7
8
9
9
10
14
14
15
16
18
19
19
20
20
21
22
23
27
28
29
30
32
33
34
35
42
43
44
47

Module 1: Organizing Data – The Frequency Distribution
Exercise 1 Solution
Step 4: Select the endpoints (beginning point and end point) of each class interval.
Step 5: Determine the frequency (F) in each class interval.
Step 6: Determine the midpoint (MP) of each class interval.
6
7
8
9
9
10
6
14
14
15
16
4
18
19
19
20
20
21
22
23
8
27
28
29
3
30
Class Interval
F
MP
6 to under 12
6
9
12 to under 18
4
15
18 to under 24
8
21
24 to under 30
3
27
30 to under 36
5
33
36 to under 42
0
39
42 to under 48
4
45
n =
30

Module 1: Organizing Data – The Frequency Distribution
Exercise 1 Solution
Step 7: Determine the relative frequency of each class interval.
Step 8: Determine the cumulative frequency of each class interval.
Note: As a general rule in this class, always round 4 decimal places unless the digits end completely before 4 decimal
places. For example, if the answer is 1.5 exactly, you don’t have to write 1.5000.
But if it’s 1.49876943, the correct
answer is 1.4988. Excel will round for you to any number of decimal places you tell it.
Class Interval
F
MP
RF
CF (%)
CF (Raw)
6 to under 12
6
9
0.2000
0.2000
6
12 to under 18
4
15
0.1333
0.3333
10
18 to under 24
8
21
0.2667
0.6000
18
24 to under 30
3
27
0.1000
0.7000
21
30 to under 36
5
33
0.1667
0.8667
26
36 to under 42
0
39
0.0000
0.8667
26
42 to under 48
4
45
0.1333
1.0000
30
n =
30

Module 1: Organizing Data – The Frequency Distribution
Exercise 2 Solution
Table 2.3
Step 1: Find the range. Sort data into ascending order. 89-51 =
38
Step 2: Decide how many classes the data will be grouped into.
6
(Given)
Step 3: Determine the width (w) of the class intervals.
W = Class Width (W) =
= = 6.3333
Will round up to
6.5
•
66
89
79
62
85
72
88
73
72
83
79
86
82
82
60
81
88
80
82
69
65
69
85
70
51
51
83
82
64
59
77
51
51
59
60
62
64
65
66
69
69
70
72
72
73
77
79
79
80
81
82
82
82
82
83
83
85
85
86
88
88
89

Module 1: Organizing Data – The Frequency Distribution
Exercise 2 Solution
Step 4: Select the endpoints (beginning point and end point) of each class interval.

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- Spring '14
- DebraACasto
- Frequency distribution, 2008 in film