STA429/1007 Assignment 7

Quiz on Friday March 9th at 12:10 p.m.


We're going to use the Poverty Data again. This time the dependent variable is the average of the life expectancies of women and men. Call this variable "life expectancy." The independent variables for this assignment will be Gross National Product, Country Group represented by 5 dummy variables, and product terms for the interactions. Please carry out analyses to answer the following questions. I did it using a single model statement and several custom F tests.

  1. For each country group, there is a regression line relating GNP to life expectancy. Are the slopes of all the lines parallel?
    1. Answer the question YES or NO.
    2. What is the numerical value of the test statistic? The answer is a number.
    3. What is the p-value? The answer is a number.
    4. Do you reject the null hypothesis? Answer Yes or No. Are the results statistically significant? Answer Yes or No.
  2. Are the regression lines for South America/Mexico and Asia parallel?
    1. Answer the question YES, NO or NO CONCLUSION.
    2. What is the numerical value of the test statistic? The answer is a number.
    3. What is the p-value? The answer is a number.
    4. Do you reject the null hypothesis? Answer Yes or No. Are the results statistically significant? Answer Yes or No.
  3. For the rich countries (Group 3)
    1. What is the estimated intercept of the regression line? The answer is a single number.
    2. What is the estimated slope of the regression line? The answer is a single number.
  4. For the African countries (Group 6)
    1. What is the estimated intercept of the regression line? The answer is a single number. It is okay to use a calculator and write the answer on the printout.
    2. What is the estimated slope of the regression line? The answer is a single number. It is okay to use a calculator and write the answer on the printout.
  5. For the African countries (Group 6), is the slope of the regression line significantly different from zero? You need to do a custom F-test; please don't subset the data with a by statement, because that way you throw away information (from countries other than the African nations) about the common variance of the conditional distributions. It may help to write out the null hypothesis in terms of the regression coefficients. So we can compare answers without my giving it all away, my F statistic is 15.23.
    1. Answer the question Answer the question YES, NO or NO CONCLUSION.
    2. What is the numerical value of the test statistic? The answer is a number.
    3. What is the p-value? The answer is a number.
    4. Do you reject the null hypothesis? Answer Yes or No. Are the results statistically significant? Answer Yes or No.
  6. Make sure you can interpret the overall F test, and also the t-tests that are produced by default.

Please bring your log and list file to the quiz.