We Took a Sample of Children Who Had Been Learning

Multiple Choice

We took a sample of children who had been learning to play a musical instrument for five years. We measured the number of hours they spent practising each week and assessed their musical skill by how many of 8 increasingly difficult exams they had passed. We also asked them whether their parents forced them to practise or not (were their parents pushy?) . What does the following graph show?

A) The more time spent practising, the more musically skilled the children were and this relationship was stronger for those who had pushy parents compared to those who did not.
B) The more time spent practising, the more musically skilled the children were, and this relationship was stronger for children who did not have pushy parents than for those who did.
C) Children with pushy parents always passed more grade exams than those without.
D) Practice causes better exam performance.