In [1]:

    

35/250


    

    
Out[1]:





[1] 0.14

In [4]:

    

n_1 = 1037
p_1 = 493/n_1

n_2 = 1028
p_2 = 596/n_2



CL = 0.95

SE = sqrt(   (p_1*(1-p_1)/n_1)+(p_2*(1-p_2)/n_2)   )
z_star = round(qnorm((1-CL)/2, lower.tail=F),digits=2)
ME = z_star*SE

c((p_1-p_2)-ME, (p_1-p_2)+ME)


    

    
Out[4]:





[1] -0.14718610 -0.06152731

In [6]:

    

sqrt(0.3*0.7/50)


    

    
Out[6]:





[1] 0.06480741

In [ ]: