With n = 20 guesses and p = 0.2 for a correct answer, find P(at least 6 correct answers).

In do the following: If the requirements of np ≥ 5 and nq ≥ 5 are both satisfied, estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution; if np < 5 or nq < 5, then state that the normal approximation should not be used.