When girls are educated in single-sex secondary schools, they tend to do better academically than girls who attend mixed-sex schools. Since Alice achieved higher grades than any other woman in her first year at the university, she was probably educated at a single-sex school.
The flawed reasoning used in the argument above is closely paralleled by the statement: When babies are taught to swim, they have more than the average number of ear infections as they grow up. Janice has more ear infections than any other person at the local swimming club, so she probably was taught to swim when she was a baby.