Question

A student scores 75, 85, and 90 on their math quizzes, with weights of 20%, 50%, and 30%.(1 point) Their weighted average score is

Answer 1

To calculate the weighted average score, you can use the formula:

\[
\text{Weighted Average} = \frac{(x_1 \cdot w_1) + (x_2 \cdot w_2) + (x_3 \cdot w_3)}{w_1 + w_2 + w_3}
\]

where \( x_i \) are the scores and \( w_i \) are the weights.

Given the scores and their respective weights:
- Score 1: 75 with a weight of 20% (0.20)
- Score 2: 85 with a weight of 50% (0.50)
- Score 3: 90 with a weight of 30% (0.30)

Now we apply the values:

\[
\text{Weighted Average} = (75 \times 0.20) + (85 \times 0.50) + (90 \times 0.30)
\]

Calculating each term:

1. \( 75 \times 0.20 = 15 \)
2. \( 85 \times 0.50 = 42.5 \)
3. \( 90 \times 0.30 = 27 \)

Now add these values together:

\[
15 + 42.5 + 27 = 84.5
\]

Thus, the weighted average score is:

\[
\text{Weighted Average} = 84.5
\]

So, the student's weighted average score is **84.5**.