Suppose that the probability p of a success on any trial of a binomial distribution equals 0.80. For which value of the number of trials, n, would the normal distribution provide a good approximation to the binomial distribution?
A) 25 .
B) 20 .
C) 10 .
D) 15 .

Question

Suppose that the probability p of a success on any trial of a binomial distribution equals 0.80. For which value of the number of trials, n, would the normal distribution provide a good approximation to the binomial distribution? 
A)  25 . 
B) 20 . 
C)  10 . 
D)  15 .

Quizplus · Accepted Answer

The normal approximation to the binomial distribution is appropriate when both np and n(1-p) are greater than or equal to 5. For n = 25, np = 25*0.80 = 20 and n(1-p) = 25*0.20 = 5, both of which satisfy the condition.

Suppose That the Probability P of a Success on Any