Answer:
np > 10, and n(1 – p) > 10.
Step-by-step explanation:
The normal approximation is used when np>10 and n(1-p)>10.
Here, sample size=n=100 and p=0.42.
So,
np=100*0.42=42>10
n(1-p)=100(1-0.42)=100*0.58=58 >10
As, np>10 and n(1-p)>10 so, the normal distribution can be use to approximate the probability that more than 38 of the sampled people had their most recent eye examination in the previous year.