Contents
- Title
page
- You
do a study of students' drinking habits...
- Your
sample mean is 10.54
- You
think you learned something, .... until ....
- They
did the same thing, but got different results
- Their
mean was 12.72. How could this be?
- Sampling
variablity?
- So
you look for other studies and find that ....
- If
you drew all possible samples from this population ...
- The
Sampling Distribution of Sample Means
- The
Sampling Distribution has useful properties
- Because
it is Normal, 68% of all means ....
- Its
standard deviation can be estimated: the Standard Error of the Mean
- You
know how to estimate the population's standard deviation
- How
to estimate the Standard Error of the Mean
- You
use information about sample statistics to estimate population parameters
- This
technique is based on four assumptions
- Standard
errors are measures of sampling variability
- Example:
Say you want to know how many speeding tickets the typical professor
has received
- Your
sample's mean was 12. How good is this as an estimate of the population's
mean?
- How
to estimate the standard error of the mean
- What
do you do with the SEM?
- How
do you do this with your standard error of the mean?
- A picture
showing how 95% of sample means are within +/- 1.96 SEM of the population
mean
- A picture
showing how you can be 95% certain that .....
- You
can be 95% certain that your sample...
- So,
when you use your sample mean to estimate the population mean, ....
- A picture
showing 68% and 95% of sample means
- Blank
Slide
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Information:
Sampling Distributions
Last updated:
May 29, 2006
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(c)
Copyright 2006 William D. Richards
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