This is a simple data set provided by Chatterjee and Price (1977, p. 108) that serves as a known example of heteroscedasticity.
Format
A data frame with 50 observations on the following 6 variables.
statea character vector for the state
regiona character vector for the Census region
urbanpopa numeric vector for the number of residents (per thousand) living in urban areas in 1970
incpca numeric vector for income per capita in 1973
popa numeric vector for residents (per thousand) under 18 years of age in 1974
edexppca numeric vector for per capita public school expenditures in a state, projected for 1975.