please suggest me................
i can well understand and solve the questions of probablity and regression etc.
means if i am given with a problem , using the formulas i can reach the exact answer. but how these formulas / athematical models are derived i can not understand. i tried to understand it from sher Muhammad book, but ended in my mind blank and my mood agressive. what you people suggest, is i enough to solve question or should i have grip on derivation of these formulas??

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