Ms. Lopez, the girls' basketball coach, needs to pick a 5th grader for the school's free-throw competition. In the last practice, Amy made 2 baskets out of 3 tries, Mariam made 7 out of 10 free-throws, and Emily made 60% of her free-throws. Mariam should be picked for the contest to give the 5th graders the best chance of winning since she made the highest percentage of free-throws out of the three girls.