A data set for a canonical case of a Simpson's paradox, useful for in-class instruction on the topic.
Format
A data frame with 50 observations on the following 8 variables.
- state
- a character vector for the state 
- expendpp
- a numeric vector for the current expenditure per pupil in average daily attendance in public elementary and secondary schools, 1994-95 (in thousands of dollars) 
- ptratio
- a numeric vector for the average pupil/teacher ratio in public elementary and secondary schools, Fall 1994 
- tsalary
- a numeric vector for the estimated average annual salary of teachers in public elementary and secondary schools, 1994-95 (in thousands of dollars) 
- perctakers
- a numeric vector for the percentage of all eligible students taking the SAT, 1994-95 
- verbal
- a numeric vector for the average verbal SAT score, 1994-95 
- math
- a numeric vector for the average math SAT score, 1994-95 
- total
- a numeric vector for the average total SAT score, 1994-95