7.- Acid rain from the burning of fossil fuels has caused many ofthe lakes around the world to become acidic. The biology in these lakes often collapses because ofthe rapid and unfavorable changes in water chemistry. A lake is classified as nonacidic if it has a pH greater than 6. Researchers measured the pH of high mountain lakes in the Southern Alps. These data are approximately normal. The pH levels for 15 lakes is presented in the list below. At the 5% signicance level, do the data provide sufcient evidence to conclude that, on average, high mountain lakes in the SouthernAlps are nonacidic? 12 "L3 6.1 6.9 6.6 1.3 6.3 5.5 6.3 6.5 5.7 6.9 6.7 7.9 5.8 For these data 2? = 6.6 and s = 0.672 To answer this question provide the following elements to perform the hypothesis test: a) Define He: Is) Define Ha: c} You will use [circle your answer}: the 2 statistic the t statistic d) Given that c: = 0.05, define the critical valuels): e) The Rejection Region for this test is: f) The observed value of the test statistic is: g} Your conclusion is {circle vouranswer}: these lakes are not acidic these lakes are acidic h) The p-value for this test is: so you: Keep Ho Reject Ho