When watching toddlers, Sidney wants to test the hypothesis that some toys are more fun to play with than others. He decides to compare "fun" toys (trucks) with "unfun" toys (baby dolls). He also wishes to see the gender difference as an independent variable.
A) What kind of design is needed?
B) Add illustration.
C) 20 toddlers are needed per cell, how many toddlers are needed for this experiment?