Measures of Dispersion and Variability: Range, QD, AD and SD
Statistics: how to do histogram
1.
2. Ex. 3.1: Analysis of Long-Distance Telephone Bills
• n=200
• Smallest obs.=$0; Largest=$119.63
• No. of classes: based on n=200; 7-9 @ 9-10
classes (p.35)
• Class interval width= (largest-smallest)/No. of
classes = (119.63 -0)/8 = 14.95 ≈ 15 (convenient
value!)
• Upper & lower interval limits?
3. In Excel:
• File/ Open/ Folder:DataSets/ Folder:excel
files/ Folder:Ch3/ Xm03-01.xls – To open data
file
• Tools/ Data Analysis/ Histogram/ OK/ Specify
the Input Range & the Bin Range/ Click Chart
Output/ Click Labels if the 1st row contains
names/OK
4. To remove the gaps, place the cursor over one of the rectangles &
click the RHS button of the mouse. Click (with LHS button) Format
Data Series… Select Gap Width & use the slider to change the no.
from 150 to 0.