1.2 Sinusitis and antibiotics:  Researchers studying the effect of antibiotic treatment for acute sinusitis compared to symptomatic treatments randomly assigned 173 adults diagnosed with acute sinusitis to one of two groups: treatment or control. Study participants received either a 10-day course of amoxicillin (an antibiotic) or a placebo similar in appearance and taste. The placebo consisted of symptomatic treatments such as acetaminophen, nasal decongestants, etc. At the end of the 10-day period patients were asked if they experienced significant improvement in symptoms. The distribution of responses is summarized below.
(please round answers to within one hundredth of a percent)

	Significant improvement: Yes	Significant improvement: No	Total
Treatment	70	27	97
Control	58	18	76
Total	128	45	173

a) What percent of patients in the treatment group experienced a significant improvement in symptoms? %
b) What percent of patients in the control group experienced a significant improvement in symptoms? %
c) Based on your finding in the previous two parts, which treatment appears to be more effective for sinusitis? Explain your reasoning.

d) Do the data provide convincing evidence that there is a real difference in the improvement rates of sinuitis symptoms? Or do you think that the observed difference might just be due to chance?