Elementary Statistics: Picturing the World (6th Edition)

n = 20, p = 0.78, q = 0.22 np = 20 x 0.78 = 15.6 nq = 20 x 0.22 = 4.4 Remember: If np $\geq$ 5 and nq $\geq$ 5, we can use the normal distribution to approximate the binomial. np $\geq$ 5 but nq $\lt$ 5, so we cannot use the normal distribution to approximate the binomial.