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 __

1 answer

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.