McGraw-Hill OnlineMcGraw-Hill Higher EducationLearning Center
Student Center | Instructor Center | Information Center | Home
Full Study Guide
Guide to Electronic Research
Internet Guide
Study Skills Primer
Statistics primer
Appendices
Learning Objectives
Chapter Overview
Fill in the Blanks
Definitions
Flashcards
Symbols and Formulas
Problems
SPSS Exercises
Self-Test
Feedback
Help Center


Thorne and Giesen Book Cover
Statistics for the Behavioral Sciences, 4/e
Michael Thorne, Mississippi State University -- Mississippi State
Martin Giesen, Mississippi State University -- Mississippi State

Measures of Central Tendency

Symbols and Formulas

SYMBOLS

SymbolStands For

Momode
Mdmedian
<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=gif:: ::/sites/dl/free/0072832517/55314/c5_s1.gif','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (0.0K)</a> sample mean
Scapital sigma, indicates to sum the following values
<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=gif:: ::/sites/dl/free/0072832517/55314/c5_s2.gif','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (0.0K)</a> deviation of a score from the mean
mpopulation mean, read "mu"

FORMULAS

Formulas 5-1 and 5-2. Equations for computing the sample mean

<a onClick="window.open('/olcweb/cgi/pluginpop.cgi?it=gif:: ::/sites/dl/free/0072832517/55314/c5_f1.gif','popWin', 'width=NaN,height=NaN,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (0.0K)</a>

Formula 5-1 tells you to add all the Xs or scores and then to divide the result by the total number of scores (N). In a frequency distribution, N is the sum of frequencies. Formula 5-2 tells you to multiply each score by its frequency before summing and dividing by N.