4. [14 points] A pollution-control inspector suspected that a riverside community was releasing semi-treated sewage into
Posted: Thu May 05, 2022 9:14 pm
4. [14 points] A pollution-control inspector suspected that a riverside community was releasing semi-treated sewage into a river and this, consequently, was changing the level of dissolved oxygen of the river. To check this, he drew 17 randomly selected specimens of river water at a location above the town and another 17 specimens below. The dissolved oxygen readings, in parts per million, are given in the following table. Above Town Below Town 5.2 4.2 4.8 4.4 5.1 4.7 5.0 4.9 4.9 4.6 4.8 4.8 5.0 4.9 4.7 4.6 4.7 5.1 5.0 4.3 4.7 4.4 5.1 4.7 5.0 4.9 4.9 4.8 4.9 4.7 5.0 4.4 5.1 4.7 Give a complete analysis of these data using a confidence interval with 99% confidence.