12.6, 5.6,-1.4,-8.4,-15.4
what is this sequence in explicit formula

Will give the box plots below show the math scores of students in two different classes: class a 55 72 75 89 95 class b 55 70 75 94 100 based on the box plots, which statement is correct? a: the median score of class a is greater than the median score of class b. b: the lower quartile of class a is greater than the lower quartile of class b. c: the upper quartile of class a is greater than the upper quartile of class b. d: the maximum score of class a is greater than the maximum score of class b.