Differences Between Population Averages. Testing the Difference Is there a difference between two...
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Between Population Averages
Differences Between Population Averages. Testing the Difference Is there a difference between two populations? Null Hypothesis: H 0 or Alternate Hypothesis:
Testing the Difference Is there a difference between two
populations? Null Hypothesis: H 0 or Alternate Hypothesis: H a or
Test Statistic: If Z is too large or too small, reject Null
Hypothesis
Slide 3
The Wallace and Gromit Hypothesis Potential Hypothesis about
the Wallace and Gromit (W&G): Males prefer W&G to Females
Greeks prefer the W&G over independents If you have heard about
W&G you will prefer them over people who have not heard of the
W&G If you have watched the W&G you will prefer them over
people who have not watched the W&G If you have lived outside
the USA for more than 6 months you will prefer W&G over people
who have lived in the USA A greater percentage of people who have
lived outside of the USA have watched W&G previously
Slide 4
The Wallace and Gromit Hypothesis
Slide 5
Slide 6
Slide 7
Hypothesized Mean How Unusual is Z = -0.858?
Slide 8
Slide 9
The Wallace and Gromit Hypothesis p-value pr(z 0.858) =
2xpr(z>0.858) = 2x0.1949 = 0.3898
Slide 10
Dummy Variable Regression Formula Rating (like W&G):
Overall mean, Average for Female: Adjustment for being Male
Adjustment: Dummy Variable: Error Term to Represent
Uncertainty:
Slide 11
Dummy Variable Regression Data Observed Rating: How much like
W&G Dummy Variable: Identifies Gender
Slide 12
Dummy Variable Regression Estimate For Average Female Estimate
For Average Male because
Slide 13
Regression Output, Using SPSS
Slide 14
Is there a difference? Automatic Hypothesis Test is Conducted
by SPSS Test 1-- Null Hypothesis: H 0 Test 2-- Null Hypothesis: H
0
Slide 15
Is there a difference? If t is far away from zero reject the
Null Hypothesis The t-statistic for :
Slide 16
Is there a difference? If t is far away from zero reject the
Null Hypothesis The t-statistic for How unusual is this
t-statistic?
Slide 17
Is there a difference? If t is far away from zero reject the
Null Hypothesis The t-statistic for How unusual is this
t-statistic? sig = p-value If p-value < 0.05, reject
Slide 18
Is there a difference? If t is far away from zero reject the
Null Hypothesis The t-statistic for :
Slide 19
Is there a difference? If t is far away from zero reject the
Null Hypothesis The t-statistic for : How unusual is this
t-statistic?
Slide 20
Is there a difference? If t is far away from zero reject the
Null Hypothesis The t-statistic for : How unusual is this
t-statistic? sig = p-value If p-value < 0.05, reject
Slide 21
Dummy Variable Regression Estimate For Average Female
because
Slide 22
Dummy Variable Regression Estimate For Average Female Estimate
For Average Male because
Slide 23
Difference Not Significant Run the Analysis Again Using
Slide 24
Difference Not Significant Run the Analysis Again Using No
difference between Male and Female, use the overall average.
Slide 25
Designing The Lion King Assume That There Were 4 Different
Jokes That Could Have Been Used. Which Joke Should They Use?
Slide 26
The Data 500 Randomly Chosen People Saw one of Four Different
Version of the Lion KingDifferent Jokes for Each Version. The Rated
the Lion King on a likert Scale of 1 to 7 With Regards to How Much
the Enjoyed the Lion King.
Slide 27
The Data
Slide 28
Dummy Variable Regression Need 3 Dummy Variables To Describe 4
Categories
Slide 29
Dummy Variable Regression Estimate For Average Viewer That Saw
Joke 1?
Slide 30
Dummy Variable Regression Estimate For Average Viewer That Saw
Joke 1? Estimate For Average Viewer That Saw Joke 2?
Slide 31
Dummy Variable Regression Estimated Response for Average Viewer
that Saw Joke 1?
Slide 32
Dummy Variable Regression Increase in Response if They Saw Joke
2 instead of Joke 1
Slide 33
Dummy Variable Regression Is There a Difference Between
Response for Joke 1 the Joke 2?
Slide 34
Dummy Variable Regression Is There a Difference Between
Response for Joke 1 and Joke 3?
Slide 35
Dummy Variable Regression Is There a Difference Between
Response for Joke 2 and Joke 3?
Slide 36
Analysis of Variance Analysis of Variance (ANOVA) Allows for
Testing Whether Means are Different
Slide 37
Analysis of Variance Analysis of Variance (ANOVA) Allows for
Testing Whether Means are Different Tests the Claim that Each Group
Has the Same Average Value
Slide 38
Analysis of Variance Analysis of Variance (ANOVA) Allows for
Testing Whether Means are Different Tests the Claim that Each Group
Has the Same Average Value Is Based on Analyzing different types of
Variance Variance From Individuals with-in a group Variance Between
Different Groups
Slide 39
Overall Average Sum of Squares: Between Groups Sum of Squares:
With-in Groups If Between Group Variance is Large Compared to
With-in Group Variance, Reject the Idea that All of the Groups have
the Same Mean.
Slide 40
ANOVA Output from SPSS F-statistic Tests Hypothesis that Each
Group has the Same Mean (Average Value).
Slide 41
ANOVA Output from SPSS F-statistic Tests Hypothesis that Each
Group has the Same Mean (Average Value). Large F-statistic, Reject
the Hypothesis. At least two Groups have Different Means
Slide 42
ANOVA Output from SPSS Joke 4 is Different from Joke 1, 2 and
3. Joke 1 and 3 are not Different from each other. They are
Different from Joke 2 and 4. Joke 2 is Different from Joke 1, 3 and
4.