An experiment studying the effects of nutritional supplement on hair loss in women was conducted. In the experiment, women with stage 1 hair loss were assigned at random to one of two groups. One group was a control group who did not receive a nutritional supplement. Of the 39 women in this group, 20 showed increased hair density at the end of the study period. Those in the second group received a nutritional supplement. Of the 80 women in the supplement group, 70 showed increased hair density at the end of the study period. Is there convincing evidence that the proportion with increased hair density is greater for the supplement treatment than for the control treatment