Reference no: EM132522628
1. This past fall, temperatures in a particular city seemed to fluctuate tremendously. The days often felt like summer and the nights often felt like winter. A weather analyst selected a simple random sample of 9 days from this past fall and recorded the high and low temperature in Fahrenheit in this city for each of the days.
Day 1 2 3 4 5 6 7 8 9
High Temp 78 85 72 82 78 77 80 78 82
Low Temp 42 50 44 48 48 45 45 41 47
(a) Make a dotplot of the difference (High - Low) in temperature for each day.
(b) Historically, fall high and low temperatures on a given day differ by 30 °F, on average. Describe what the graph reveals about whether temperatures differed more than usual this past fall.
(c) Calculate the mean difference in temperature and the standard deviation of the differences. Interpret the mean difference.
(d) A 99% confidence interval for the true mean difference (High - Low) in daily temperature is (30.242, 36.869). Based on this interval, can you conclude that the daily temperature differed by more than 30°F, on average, this fall? Why or why not?