1.	Since S(p)=sqrt(0.2*0.8/400)=sqrt(0.0004)=0.02 then
	z1=(0.18-0.20)/0.02=-1 and z2=(0.22-0.20)/0.02=1. Hence 
        68.27% of samples of size 400 would result in sample 
        proportions between 18% and 22%.

2.	Since S(p)=sqrt(0.2*0.8/64)=sqrt(0.0025)=0.05 then
	z=(0.10-0.20)/0.05=-2. Hence (100-95.45)/2=2.275% of
        samples of size 64 would result in sample proportions
        proportions less than 10%.