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STA 6127 – Spring 2010
Homework 4/5 – Due 3/31/10
Analysis of Covariance
Using the cloud seeding data, complete the following problems for all tests use
α=0.05
significance level).
Fill in answers on this form, and include computer output.
1)
Use the 2sample ttest to test whether there the true mean amount of rain differs between seeded and
unseeded conditions in the test area.
2)
Write out the model for the Analysis of Covariance, stating all parameters and their meanings (assume
no interaction for this part and the next part).
3)
Use the Analysis of Covariance to test whether the true mean amount of rain differs between the
seeded and unseeded conditions, controlling for the amount of rain in the control area.
4)
Test whether there is an interaction between seeding condition and amount of rainfall in the control
area. (You will need to create a variable that is the product of seeddum and cntrltot).
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View Full DocumentModel Building
1)
For the Crime data, we have the following variables:
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 Spring '08
 Mukherjee
 Covariance, Variance

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