21.29 Organic Food. A 2014 Consumer Reports National Research Center survey on food labeling found that 49% of a random sample of 1004 American adults report looking for information on food labels about whether the food they are purchasing is organic. Use this survey result and Table 21.1 to give 70%, 80%, 90%, and 99% confidence intervals for the proportion of all adults who feel this way. What do your results show about the effect of changing the confidence level?