Math Problem Statement

What is the weighted average of the three numbers with the weights shown?

Solution

To solve the weighted average problem in the image:

Given dataTo solve the weighted average problem in the image:

Given

  • Numbers: 3-3, 2-2, 66
  • Corresponding weights:
    w3=13,w2=12,w6=16w_{-3} = \frac{1}{3}, w_{-2} = \frac{1}{2}, w_6 = \frac{1}{6}

The formula for the weighted average is:

Weighted Average=(xiwi)wi\text{Weighted Average} = \frac{\sum (x_i \cdot w_i)}{\sum w_i}

Step 1: Calculate the weighted sum (xiwi)\sum (x_i \cdot w_i)

(xiwi)=(3×13)+(2×12)+(6×16)\sum (x_i \cdot w_i) = (-3 \times \frac{1}{3}) + (-2 \times \frac{1}{2}) + (6 \times \frac{1}{6}) =1+(1)+1=1= -1 + (-1) + 1 = -1

Step 2: Calculate the sum of the weights wi\sum w_i

wi=13+12+16\sum w_i = \frac{1}{3} + \frac{1}{2} + \frac{1}{6}

Finding a common denominator (which is 6): wi=26+36+16=66=1\sum w_i = \frac{2}{6} + \frac{3}{6} + \frac{1}{6} = \frac{6}{6} = 1

Step 3: Compute the weighted average

Weighted Average=11=1\text{Weighted Average} = \frac{-1}{1} = -1

Final Answer:

The weighted average is 1-1.

Would you like further clarification or more details?

Here are 5 related questions to consider:

  1. How do you calculate the weighted average for more than three values?
  2. What happens if the sum of the weights is not 1?
  3. Can a weighted average be greater than any of the original numbers?
  4. How would the result change if the weights were distributed differently?
  5. In what scenarios is calculating a weighted average useful in real life?

Tip: Always ensure the sum of the weights equals 1 to simplify weighted average calculations.

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Math Problem Analysis

Mathematical Concepts

Weighted Average
Arithmetic
Algebra

Formulas

Weighted Average = (Sum of (value * weight)) / (Sum of weights)

Theorems

Arithmetic Mean Theorem

Suitable Grade Level

Grades 8-10