The table shows preferences of dancing or playing sports for male and female students: Do you prefer dancing or playing sports?
Playing sports Dancing Row totals
Male students 18 16 34
Female students 18 35 53
Column totals 36 51 87

Mason mistakenly calculated the conditional relative frequency for female students who prefer playing sports to be 21%. What statistic did Mason actually calculate, and what should he have done differently?
He calculated the marginal relative frequency of female students who prefer playing sports. The conditional relative frequency for female students who prefer playing sports is 34%.
He calculated the joint relative frequency of female students who prefer playing sports. The conditional relative frequency for female students who prefer playing sports is 50%.
He calculated the marginal relative frequency of female students who prefer playing sports. The conditional relative frequency for female students who prefer playing sports is 50%.
He calculated the joint relative frequency of female students who prefer playing sports. The conditional relative frequency for female students who prefer playing sports is 34%.