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Finding the Fourth Proportional to 782.34, 1,079.42 and 487.65

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Solution

The fourth proportional to 782.34, 1,079.42 and 487.65 is: 672.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.34 : 1,079.42 = 487.65 : x
  2. Step 2: Convert to fraction form
    782.34/1,079.42 = 487.65/x
  3. Step 3: Cross multiply
    782.34x = 1,079.42 × 487.65
  4. Step 4: Simplify right side
    782.34x = 526,380.77
  5. Step 5: Solve for x
    x = 526,380.77/782.34
  6. Step 6: Final answer
    x = 672.83

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.