How to compute Final Grade with assignment weightings?

Question

I have just finished the Final for my Computer Hardware course, and I'm trying to figure out where my grade currently stands. The way the class is broken up is 50% weight for the homework, 25% for the Midterm, and 25% for the Final.

Looking at things straight forward, there are 14 graded entries for 100 points each.

Assignment                            Possible Points    Score      Grade
Hw 1 - 1.13-15, 2.15, 2.19            100.00             100.00     A
Lab 1 - 7-SEGMENT Display             100.00             100.00     A
Hw 2 - 3.24, 29, 4.3, 7, 32           100.00              90.00     A
Lab 2 - 8 * 8 Memory Register         100.00             100.00     A
Midterm                               100.00              79.00     C
Hw 3 - 5.5, 11, 23, Marie 4.3, 14     100.00             100.00     A
Lab 3 - Build an Alu                  100.00             100.00     A
Hw 5 - 8.1, 8, 12, 15, 22             100.00             100.00     A
Lab 5 - Build Cpu Use Alu From Lab3   100.00              75.00     C
Hw 6 - 10.14, 11.6, 12.8, 13.9, 14.2  100.00             100.00     A
Lab 6 - Memory Unit & Bus on Cpu      100.00               0.00
Hw 7 - 1+ Questions for Review        100.00             100.00     A
Lab 7 - Test Program for Pc           100.00               0.00
Final                                 100.00               ?.?? 

As things stand without the Final, I'm showing (according to the online grade book) 79.95%. I feel like the final went good, but I'm not sure how to Account for the weightings of 50% for homework, 25% Midterm, 25% Final.

I'm trying to figure out how to compute, if say, the grade on my final was a 79% just like on my Midterm.

Can anyone show me the proper methodology here?

Answer 1

Homework + lab total: $$1 + 1 + .9 + 1 + 0 + 0 + 1 + 1 + 1 + .75 + 1 + 0 + 1 + 0 = 9.65$$ Homework + lab average: $$9.65/14 = 0.689286.$$ I have assumed that there are 7 homework and lab assignments each, and that the missing value for Homework 4 and Lab 4 are zero. If that is not the case, adjust the values accordingly.

Midterm = 0.79. Suppose the final is $x$, where $0 \le x \le 1$. Then the final grade is $$0.689286 \cdot 0.50 + 0.79 \cdot 0.25 + 0.25 x.$$ The minimum $x$ required to get a score of $0.8$, a B, is over 100%, meaning it is not possible to get anything higher than a C. If, however, there was no Assignment 4, then the calculation would be $x = 0.8016$, meaning you would need just over 80% on the final to get a B. Even under this assumption, there is no possibility of getting an A.

From the information you provided that your grade so far is 79.95%, it appears that there was no Homework/Lab 4. That calculation presumes that there is no final, and that the homework + labs are worth twice the midterm. To get the overall score from this, you would simply renormalize: $$0.7995 \cdot 0.75 + 0.25 x$$ is your overall score if $x$ is the score on your final.

Answer 2

Take the sum of the weight*score, divide by sum of weight.

In your case, you should also apply a new weight for homework: with 12 assignments, and the total weigth = 25%, the weight for each assignment is 25%/12.

Answer 3

I assume homework includes labs. Let $x$ be your score on the final.

Weighted average = $.25\cdot\frac{965}{1200}+.25\cdot\frac{79}{100}+.50\cdot\frac{x}{100}=.3985+\frac{x}{200}$.

If you score $79$ on the final, your average would be $.3985+\frac{79}{200}=.7935$. Your percentage would be $79.35\%$