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Finding the Fourth Proportional to 781.67, 1,079.17 and 487.35

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Solution

The fourth proportional to 781.67, 1,079.17 and 487.35 is: 672.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.67 : 1,079.17 = 487.35 : x
  2. Step 2: Convert to fraction form
    781.67/1,079.17 = 487.35/x
  3. Step 3: Cross multiply
    781.67x = 1,079.17 × 487.35
  4. Step 4: Simplify right side
    781.67x = 525,932.28
  5. Step 5: Solve for x
    x = 525,932.28/781.67
  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.