Assume that $X_1, X_2,\ldots X_{80}$ are independent and identically distributed with the same distribution as $X$ (hence $X_i \sim F(x)$ for all $i=1,\ldots,80$). Determine the probability that at least 70 out of these 80 random variables exceed zero.
Probability density function is: $f(x) = 1/20(x + 2)^3,\ −1 ≤ x ≤ 1.$
My plan would be to calculate $P(X > 0)$ for one $X$, and then use the Hypergeometric distribution. Is this correct?