. The EPA has been worried about phosphorus concentration in Lake Erie. They implemented an expensive environmental regulation in 2020 which was fully implemented in 2022. Phosphorus levels were sampled at eight randomly selected locations throughout the lake prior to the law's passage in 2020 and after implementation in 2022. The results, in parts per million (ppm), are listed in the table below. At the .01 level of significance, test to see if the passage of the expensive new law has been successful in reducing lake phosphorus levels. List and clearly label all eight steps. Round to 4 (FOUR) decimal places. Location 1 2345678 Before After 4.30 4.15 2.66 2.47 5.67 5.97 7.07 6.57 7.16 7.31 6.32 6.51 5.89 5.64 4.69 4.40