Question: Physical Sciences. The ozone hole is a region in the Southern Hemisphere that has increased since 1979. The mean ozone hole area (in million km2) in 2012 was 17.916 with standard deviation 5.6. Suppose 33 days are selected at random and the ozone hole is measured each day.
a. What is the probability that the sample mean ozone hole area is less than 15.5 million km2?
b. What is the probability that the sample mean ozone hole area is between 16 and 18 million km2?
c. Some researchers suggest that increased use of chemicals has caused the ozone hole area to increase. Suppose the sample mean for the 33 days is 20.7 million km2. Is there any evidence to suggest that the mean ozone hole area has increased? Justify your answer.