If np 5 and nq 5 estimate Upper Pmore than 4 with n12 and p

If np 5 and nq 5, estimate Upper P(more than 4) with n=12 and p= 0.6 by using the normal distribution as an approximation to the binomial distribution; if np <5 or nq <5, then state that the normal approximation is not suitable.

Solution

Here n= 12*0.6=7.2 and nq= n(1-p) = 12 * (1-0.6)=4.8 so nq is not greater than 5 (that is nq < 5) therefore normal approximation is not suitable.