MBA 604 Introduction Probaility and Statistics Lecture Notes
MBA 604 Introduction Probaility and Statistics Lecture Notes
MBA 604 Introduction Probaility and Statistics Lecture Notes
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2 Graphical Methods<br />
Frequency <strong>and</strong> relative frequency distributions (Histograms):<br />
Example<br />
Weight Loss Data<br />
20.5 19.5 15.6 24.1 9.9<br />
15.4 12.7 5.4 17.0 28.6<br />
16.9 7.8 23.3 11.8 18.4<br />
13.4 14.3 19.2 9.2 16.8<br />
8.8 22.1 20.8 12.6 15.9<br />
Objective: Provide a useful summary of the available information.<br />
Method: Construct a statistical graph called a “histogram” (or frequency distribution)<br />
Weight Loss Data<br />
class bound- tally class rel.<br />
aries freq, f freq, f/n<br />
1 5.0-9.0- 3 3/25 (.12)<br />
2 9.0-13.0- 5 5/25 (.20)<br />
3 13.0-17.0- 7 7/25 (.28)<br />
4 17.0-21.0- 6 6/25 (.24)<br />
5 21.0-25.0- 3 3/25 (.12)<br />
6 25.0-29.0 1 1/25 (.04)<br />
Totals 25 1.00<br />
Let<br />
k = # of classes<br />
max = largest measurement<br />
min = smallest measurement<br />
n =samplesize<br />
w =classwidth<br />
Rule of thumb:<br />
-The number of classes chosen is usually between 5 <strong>and</strong> 20. (Most of the time between<br />
7 <strong>and</strong> 13.)<br />
-The more data one has the larger is the number of classes.<br />
7