A teacher is calculating the marks for the students in her Data Management class. She assigns the following values to each category. Knowledge: 25% Application: 20% Thinking: 10% Culminating Project: 15% Final Exam: 15% Communication: 15% Kyle has not yet written his final exam, but his marks in the first five categories are 90, 79, 82, 70, and 85. a) Determine the weighted mean for Kyle before the final exam. b) How does this weighted mean differ from the unweighted mean?