Question 1105013
Ho:p1=p2
Ha:p1 ne p2
the test statistic is a z=(p1-p2)/sqrt (p1(1-p1)/n1 + p2(1-p2)/n2)); critical value is |z|>2.576
z=(0.164-0.239)/SE
SE: pi*n1+p2*n2/(n1+n2)=38/180=0.2111, so SE is 0.211*0.789(1/67+1/113)
SE=sqrt (0.0040)=0.0629
z=-1.192
p-value is 0.24
Fail to reject Ho; insufficient evidence to say that there is a significant difference.