Bowman’s Website

September 17, 2008

Statistics Notes — Standard Deviation for Grouped Data

Filed under: Statistics — Tags: — bowman @ 2:04 am

Height of males

Number of classes = 5

Data set: The heights, to the nearest inch, of 30 males

67    76    69    68    72    68    65    63    75    69
66    72    67    66    69    73    64    62    71    73
68    72    71    65    69    66    74    72    68    69

Range = 76 – 62 = 14
Class width = 14/5 = 2.8 –> 3

.

.

So, the sample mean is 69.1 inches and the sample standard deviation is about 3.48 inches.

Notice the tallies.  This distribution appears normal.  The Empirical Rule rules here.

About these ads

The WordPress Classic Theme. Create a free website or blog at WordPress.com.

Follow

Get every new post delivered to your Inbox.