Flex / AS3 chart component to display normal distribution

Question

Given a dataProvider with values ranging from 25 to 85:

public var answers:ArrayCollection = new ArrayCollection([
    {user_id: "A5", question_1: 35, question_2: 55},
    {user_id: "A6", question_1: 40, question_2: 56},
    {user_id: "A7", question_1: 45, question_2: 52},
    {user_id: "A8", question_1: 43, question_2: 50}
]);

1. How can I easily sum the frequency of each value and plot in a column chart?
2. Which flex component / as3 library would you recommend for this?

(Criteria: data binding, auto adjustment, flexibility in layout)