You investigate nitrate in runoff. To establish a baseline, you go to the lake during a dry spell and you take sample 1, n1 measurements. After the next rain storm, you return and take sample 2, n2 measurements. Obviously, the research question is: what is the difference: after - before. Explain in detail (step by step) how you would address this research question given the following scenarios and provide the most important formulas you need to do so: (a) You select 25 locations, and take both sets of measurements (n1 = n2 = 25) at these locations. (b) You use n1 = 20 and n2 = 40, and you select random locations on both occasions. (c) You use randomized locations on both occasions and you take a handheld device that indicates only whether the nitrate level is above the acceptable threshold (green light = acceptable water quality; red light = unacceptable). Since your measurements are fast, you can take a lot of samples (n1 = n2 = 78)