Question 1159617
Random sample and large enough to test using 2-sample proportion test
p1 hat for experimental is 0.2601
p2 hat for placebo is 0.2202

Ho: experimental is less than or equal to p2
Ha: experimental is more than p2
alpha=0.05 p{reject Ho|Ho true}
test statistic is a z 0.95
reject if z>1.645

test
z=(p1 hat-p2 hat)/SE
z=2.84 
p-value=0.0023

reject Ho and conclude there is ample evidence to say that there frequency of headaches as a side effect is greater in the experimental group than in the control group.