PROBLEM 1. Professor Balenciaga has reported her students' grades for several semesters and the average for all the grades of these students is 83. Her new class of 28 students seem to be higher than the average of ability and she wants to demonstrate that the current class is superior to the previous classes according to their average." Is there sufficient evidence for the class average of 86.2 and the standard deviation of 12 present to support her argument that the current class is superior? Using the 0.05 significance level.​