You can use the Stata Command:

use http://www.philender.com/courses/data/tdata1, clear

or

input method math
1 32
2 38
3 41
1 30
2 36
3 40
1 34
2 48
3 41
1 29
2 36
3 39
1 38
2 30
3 40
end

Linear Statistical Models Course