So, I wanted to figure out this “weighted average r” thing today. I’d heard the term tossed around, and it sounded kinda important, but I didn’t really get it. Time to roll up my sleeves and get my hands dirty!
Starting from Scratch
First, I needed some data. I figured the best way to learn was to just make up my own example. I grabbed a piece of paper and scribbled down some imaginary numbers. I wanted to keep thing easy to understand.
- Test 1: Score of 80 (worth 20% of the final grade)
- Test 2: Score of 90 (worth 30% of the final grade)
- Test 3: Score of 70 (worth 50% of the final grade)
Doing the Calculations
Okay, I had my numbers. Now, to start doing my process to implement weighted average.
I figured I needed to multiply each score by its weight. So, I grabbed my phone’s calculator and punched in:
- 80 0.20 = 16
- 90 0.30 = 27
- 70 0.50 = 35
Adding It All Up
I was feeling pretty good at this point. The last step, I thought, was to just add up those results:
16 + 27 + 35 = 78
Boom! There it was. My weighted average “r” (or in this case, just a weighted average grade) was 78. Not bad, not bad at all.
Understanding What I Did
After that, I thought about why this worked. It made sense: The tests that were worth more of the grade had a bigger impact on the final number. That test I bombed (the 70) hurt me, but because it was worth half the grade, it really pulled things down. If all the tests had been worth the same amount, the average would have been different (80+90+70)/3 that result is around to 80. I tried it out to check, and yep, the regular average was higher.
Final Implementation
After the experiment, I decided to put this knowledge into action. My notes from all those meetings and classes? Kinda messy. But now I can calculate how much time I “really” spent on each project, taking into account those meetings that sucked up half my day. This whole “weighted average” thing is actually pretty useful!