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Finding the Fourth Proportional to 814.32, 1,221.72 and 381.72

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Solution

The fourth proportional to 814.32, 1,221.72 and 381.72 is: 572.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.32 : 1,221.72 = 381.72 : x
  2. Step 2: Convert to fraction form
    814.32/1,221.72 = 381.72/x
  3. Step 3: Cross multiply
    814.32x = 1,221.72 × 381.72
  4. Step 4: Simplify right side
    814.32x = 466,354.96
  5. Step 5: Solve for x
    x = 466,354.96/814.32
  6. Step 6: Final answer
    x = 572.69

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.