The visibility standard index (VSI) is a measure of air pollution that is reported daily in a local newspaper. The index ranges from 0 (excellent air quality) to 200 (very bad air quality). During the winter months, the air pollution is higher and the index has a mean of about 90 (rated as fair) with a standard deviation of approximately 30. Data for 15 days is given below. Identify any points that lie outside a 95% Confidence Level (Mean plus or minus two standard deviations) using the above winter mean and standard deviation. Explain your answer. Graph the data.

DAY 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
VSI 80 115 100 90 15 10 53 75 80 110 165 160 120 140 195

You may use Excel and/or Power Point or other tools to address the items above.