Which fraction would make this equation true? 4x ? = 6 2/3

Pls! does anybody know a shortcut for answering these types of questions in the future?

Proceed as in example 3 in section 6.1 to rewrite the given expression using a single power series whose general term involves xk. ∞ n(n − 1)cnxn − 2 n = 2 − 4 ∞ ncnxn n = 1 + ∞ cnxn n = 0

What does the relationship between the mean and median reveal about the shape of the data