pineworm infestation commonly found in children can be treat

pineworm infestation, commonly found in children, can be treated with the drug pyrantel pamoate. According to the Merk Manual, The treatment is effective in 90% of cases. If 20 children with pineworm infestation are treated with pyrantel pamoate, what is the variance of the number cured?

Solution

n=20; p = 0.90; 1 = 0.10

Variance ( npq )= 20*0.9*0.1 = 1.8