Lauretta J. Fox
A frequency distribution can be represented graphically on a
histogram
. A histogram is a bar graph on which the bars are adjacent to each other with no space between them. To construct a histogram, arrange the data in equal intervals. Represent the frequencies along the vertical axis and the scores along the horizontal axis. The true limits of any interval extend one half unit beyond the endpoints established for the interval and are represented in this manner on the horizontal axis. For example, the true limits of the interval 7680 are 75.5 and 80.5. To get the proper perspective, the vertical axis should be approximately threefourths as long as the horizontal axis.
Example
:
Illustrate the following set of measurements on a histogram:
72

82

56

73

87

89

72

86

88

76

86

69

84

85

62

97

70

78

84

93

70

60

91

76

83

94

65

72

92

81

98

78

88

76

96

89

90

83

74

80

Solution
:
Scores

Frequency

96100

3

9195

3

8690

4

8185

6

7680

8

7175

5

6670

3

6165

2

5660
(figure available in print form)
Exercises
:

1.) Construct a histogram for the following scores earned by a group of high school students on a Scholastic Aptitude Examination.
Score

Number
of
Students

400449

20

450499

35

500549

50

550599

50

600649

40

650699

20

700749

10


2.) The weights of 40 football players are as follows:
210

181

192

164

170

186

205

194

178

161

175

195

172

188

196

182

206

188

165

202

178

163

190

198

187

198

174

172

183

208

185

162

203

172

196

184

185

176

197

184

a.) Construct a frequency distribution for the given data.
b.) Make a histogram for the given data.