Collect Homework 1  (Go to practice/homework problems if you want another copy)

Review Homeworked on percentiles (from pp 47-48, #1-4) - no questions

• Working with Grouped Frequencey Distributions
• Determined Percentile
• refer to formulae 3.01 on p. 46 in text
• Also determined a score for a given Percentile
• refer to formulae 3.02 on p. 46

• Mode
•  most frequent (common) score
•  fits all levels/scales of measurement
•  only one appropriate for nominal data
• Median
•  middle-most score
•  must have at least ordinal data
• Finding the Median
1.  Determine the total number of scores (N)
2.  Find the position of the midpoint
 a.  If N is ODD
  midpt = (N+1)/2 th score
 b. If N is EVEN
  midpt is b/w N/2 th and (N/2)+1 th score
  if b/w 2 different scores, report higher 1
3.   Look up CF column and over to X column to identify the median score.
• Examples

• Mean 
• Arithmetic average 

• Use your stat function
• Must have interval or ratio data
• Takes into account ALL scores
• Most sensitive (especially with outliers)
• But, best measure of CT for interval & ratio

• Skewed Data

• Median is preferred to mean

• Practice problems
• Page 48, # 5 and #6
• Page 58 in text, problems #1A and #1B


Also for Friday, don't forget to:

• Create your class data file (save the file to your flash drive or google.docs)
• Bring your data file created in lab last week of attitude and height data from Tables 2.1 and 2.3 in SPSS text.
• Bring Holcomb text
• Bring flash drive
• Bring ID


Be reading Chapters 3 and 4 in textbook.
Based on: Vincent, W. J. (2005). Statistics in kinesiology (3rd ed.). Champaign, IL: Human Kinetics.

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