N Y N N N N N Y Y Y Y N N N Y N N Y N Y N Y N N N N N Y Y Y
N
Y
N
N
N
N
N
Y
Y
Y
Y
N
N
N
Y
N
N
Y
N
Y
| N | 
| Y | 
| N | 
| N | 
| N | 
| N | 
| N | 
| Y | 
| Y | 
| Y | 
| Y | 
| N | 
| N | 
| N | 
| Y | 
| N | 
| N | 
| Y | 
| N | 
| Y | 
Solution
a)
 No. of students own shares of stock among 20 (x)=8
 Sample Size(n)=20
 Sample proportion = x/n = 8/20 = 0.4
 b)
 Standard Error = Sqrt(p*(1-p)/n))
 x = Mean
 n = Sample Size,
 Sample Size(n)=20
 proportion =0.4
 Standard Error = Sqrt ( (0.4*0.6) /20) )
 = 0.1095


