Question 1

A confidence interval for the population mean number of US states Americans have visited was found to be 11.9 to 12.3. Find the midpoint of this confidence interval:

Question 2

In a survey, 15 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $44 and standard deviation of $6. Construct a confidence interval at a 98% confidence level. Give your answers to one decimal place.

Question 3

If you want a poll to have a margin of error of 3.53%, how large will your sample have to be? Round your answer to the nearest whole number. ------people?

Question 4

If you want a poll to have a margin of error of 3.55%, how large will your sample have to be? Round your answer to the nearest whole number. ------ people