Can medical clowning improve the success of in vitro fertilization? To find out, 186 women seeking in vitro fertilization were randomly assigned to either medical clowning or no medical clowning. Of the 93 women given medical clowning, 33 became pregnant (p = 33/93 = 35.4%). Of the 93 not given medical clowning, 18 became pregnant (p = 18/93 = 19.4%). What is the difference in pregnancy rates for medical clowning vs. no medical clowning? What is the 95% CI for this difference? Interpret the result: Does medical clowning significantly facilitate pregnancy?