Clinical literature reports that the duration of a typical cold is roughly 18 days. Researchers wanted to know if people tend to underestimate the duration of a typical cold, on average. They surveyed a random sample of 352 healthy adults in Georgia and asked them how long they think that a typical cold lasts. The researchers reported a 95% confidence interval of 6.9 to 8.2 days for the mean expected duration of typical cold. The researchers reported that the answers to this question were strongly right-skewed. The 95% confidence interval (6.9.8.2) they obtained is Answer 1. likely appropriate because the answers of all healthy adults in Georgia are likely to be Normally distributed given that this is such a large population. 2. appropriate despite the skewed data because the sample size is large enough to rely on the robustness of the t procedures. 3. not appropriate because the sample data are skewed. 4. not appropriate because the answers of all healthy adults in Georgia are likely not Normally distributed
