What is the average age of a group of 20 students, if 6 students are 12 years old, 8 students are 14 years old, and the remaining students are 16 years old?
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What is the standard deviation of a data set: 12, 18, 20, 22, 30?
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What is the vertex form of a parabolic function y = ax^2 with characteristics including vertex at (h,k), axis of symmetry x = h, and y-intercept at (0, c)?