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Finding the Fourth Proportional to 502.20, 691.61 and 408.78

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Solution

The fourth proportional to 502.20, 691.61 and 408.78 is: 562.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    502.20 : 691.61 = 408.78 : x
  2. Step 2: Convert to fraction form
    502.20/691.61 = 408.78/x
  3. Step 3: Cross multiply
    502.20x = 691.61 × 408.78
  4. Step 4: Simplify right side
    502.20x = 282,714.29
  5. Step 5: Solve for x
    x = 282,714.29/502.20
  6. Step 6: Final answer
    x = 562.95

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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.