Calculate Jane's weighted grade: (round to the nearest tenth)
Portion of Grade Jane's Averages
Homework 15%. 67
Labs 10% 98
Quiz 25% 75
Test 50% 95
for a straight average, you just add up the scores and divide by how many scores there are.
For a weighted average, you multiply each score by its weight (% of grade)
So, in this case, that is
(0.15*67 + 0.10*98 + 0.25*75 + 0.50*95) = 86.1
Note that the regular mean is just a special case of a weighted average, where each value is weighted by 1/4
(67+98+75+95)/4 = 1/4 *67 + 1/4*98 + 1/4*75 + 1/4*95
To calculate Jane's weighted grade, we need to multiply her average for each category by the respective weight percentage and then sum the results.
1. Multiply Jane's homework average (67) by the weight percentage (15%):
67 * 0.15 = 10.05
2. Multiply Jane's lab average (98) by the weight percentage (10%):
98 * 0.10 = 9.8
3. Multiply Jane's quiz average (75) by the weight percentage (25%):
75 * 0.25 = 18.75
4. Multiply Jane's test average (95) by the weight percentage (50%):
95 * 0.50 = 47.5
5. Sum all the results:
10.05 + 9.8 + 18.75 + 47.5 = 86.1
So, Jane's weighted grade is 86.1 (rounded to the nearest tenth).
To calculate Jane's weighted grade, we need to multiply each grade by its respective weight, and then add up the results.
First, we calculate the weighted average for each category:
- Homework: 67 (average) * 0.15 (weight) = 10.05
- Labs: 98 (average) * 0.10 (weight) = 9.8
- Quiz: 75 (average) * 0.25 (weight) = 18.75
- Test: 95 (average) * 0.50 (weight) = 47.5
Next, we add up the weighted averages:
10.05 + 9.8 + 18.75 + 47.5 = 86.1
Therefore, Jane's weighted grade is 86.1 when rounded to the nearest tenth.
15 * 67 + 10 * 98 + 25 * 75 + 50*95 = 100 * x
100 x = 1005 + 980 + 1875 + 4750
100 x = 8610
x= 86.1