Question: Acid rain has caused many lakes to become more acidic. A lake is considered nonacidic if the PH level is greater than 6. The PH level for 15 lakes was:
7.2, 7.3, 6.1, 6.9, 6.6, 7.3, 6.3, 5.5, 6.3, 6.5, 5.7, 6.9, 6.7, 7.9, and 5.8
At "alpha" = 0.05, is there enough evidence to conclude that, on average, these lakes are nonacidic?