The probability that at least 14 out of the 15 will require eyesight correction

Question

A survey showed that 79% of adults need correction for their eyesight. If 15 adults are randomly selected, find the probability that at least 14 of them need correction for their eyesight. Is 14 a significantly high number of adults requiring eyesight correction? The probability that at least 14 of the 15 adults require eyesight correction is?

Answer 1

Assuming adults are independent, then we can apply the binomial distribution to the number of adults who require eyesight correction.

This is simply given by P(X = 14) + P(X = 15) = 15C14 (0.79)^14(1-0.79)^1 + 15C15(0.79)^15 = 0.1453...