Below is an example for calculating the final grade.  See the syllabus for details and the grading scale.

Quizzes:  18, 20, 17, 18, 17, 0, 15
Minitabs:  15, 15, 10, 13, 14, 12, 5
Tests:  46, 48, 44, 34

This student's quiz percentage is (18+20+17+18+17+0+15)/(7*20) = 105/140 = 0.75.  The Minitab percentage is calculated as (15+15+10+13+14+12+5)/(7*15) = 84/105 = 0.80.  The test percentages are 46/50 = 0.92, 48/50 = 0.96, 44/50 = 0.88, and 34/50 = 0.68.  Thus, the final "class percentage" is 0.1(0.75) + 0.1(0.80) + 0.2(0.92) + 0.2(0.96) + 0.2(0.88) + 0.2(0.68) = 0.843, which is a B.

You can click here to download an Excel file that performs the above calculations.  Please feel free to use this to keep track of your grades for the semester.