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:

\[
\text{Weighted Average} = \left( \text{Score}_1 \times \text{Weight}_1 \right) + \left( \text{Score}_2 \times \text{Weight}_2 \right) + \left( \text{Score}_3 \times \text{Weight}_3 \right)
\]

Given:
- Score 1 = 75, Weight 1 = 20% (0.20)
- Score 2 = 85, Weight 2 = 50% (0.50)
- Score 3 = 90, Weight 3 = 30% (0.30)

Now calculate:

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

Calculating each term:

\[
75 \times 0.20 = 15
\]
\[
85 \times 0.50 = 42.5
\]
\[
90 \times 0.30 = 27
\]

Now add them together:

\[
\text{Weighted Average} = 15 + 42.5 + 27 = 84.5
\]

Thus, their weighted average score is **84.5**.