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Finding the Fourth Proportional to 819.29, 1,229.57 and 429.38

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Solution

The fourth proportional to 819.29, 1,229.57 and 429.38 is: 644.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.29 : 1,229.57 = 429.38 : x
  2. Step 2: Convert to fraction form
    819.29/1,229.57 = 429.38/x
  3. Step 3: Cross multiply
    819.29x = 1,229.57 × 429.38
  4. Step 4: Simplify right side
    819.29x = 527,950.62
  5. Step 5: Solve for x
    x = 527,950.62/819.29
  6. Step 6: Final answer
    x = 644.40

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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.