Math Question: In circle O with diameter AB, if angle ACB = 70 degrees, what is the measure of angle AOB?
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What is the average income (in dollars) of a household with 4 members if the first member earns $40,000, the second earns $50,000, the third earns $60,000, and the fourth earns $70,000?
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Math question: Find the derivative of f(x) = 5x^3 + 2x^2 - 7x + 9.