2. The concentrations of DOC (dissolved organic carbon) were measured at 30 different locations of a river in Spring 2020 (in mg/L). The DOC concentrations were also measured at the same locations of the river in Fall 2020. The results are summarized below: Concentration in Concentration in Spring (mg/L) Fall (mg/L) Sample mean 6.5 5.5 Sample standard deviation 0.80 0.87 Using the raw data, the following is also calculated: Sxx = 18.68 Syy = 22 Sxy = 12.68 Sy/x = 0.692 a) For a location in the river that has a DOC of 1.5 mg/L in Spring, what would you predict the Fall concentration to be, with 95% confidence? Show all the necessary calculations and clearly write your conclusion statement. (6.5 marks) b) What are different statistical analyses that you can do to ensure this prediction line is reliable? Just name them, no explanation needed. (1.5 mark)