There is growing concern over a possible causal link between consumption of diet soda and obesity. in 2013, gallup surveyed a nationally representative sample of 2027 adults about their soda consumption. in the sample, 921 adults described themselves as overweight, and 295 of them said that they mostly drank diet soda. based on these results, what is a 95% confidence interval for the proportion p of overweight american adults who mostly drink diet soda?