Question 1156451
this is a two sample proportion test with
half interval is +/- 1.96* SE is sqrt((pi(1-p1)/n1 +(p2-(1-p2)/n2))
=1.96*00.0184  where p1=0.04 and p2=0.03 and n1=n2=200
=0.0360
so 95% CI=0.01+/-0.0360 or (-0.026, 0.046) 

zero is in the interval