1)In a sample of 100 households, the mean number of hours spent on social networking sites during the month of January was 50 hours. In a much larger study,

the standard deviation was determined to be 6 hours.

Assume the population standard deviation is the same. What is the 98% confidence interval for the mean hours devoted to social networking in January?


2)Two studies were completed in Florida. One study in northern Florida involved 2,000 patients; 64% of them experienced flu-like symptoms during the month of December.

The other study, in southern Florida, involved 3,000 patients;

54% of them experienced flu-like symptoms during the same month. Which study has the smallest margin of error for a 95% confidence interval?