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Finding the Fourth Proportional to 819.35, 1,228.91 and 429.22

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Solution

The fourth proportional to 819.35, 1,228.91 and 429.22 is: 643.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.35 : 1,228.91 = 429.22 : x
  2. Step 2: Convert to fraction form
    819.35/1,228.91 = 429.22/x
  3. Step 3: Cross multiply
    819.35x = 1,228.91 × 429.22
  4. Step 4: Simplify right side
    819.35x = 527,472.14
  5. Step 5: Solve for x
    x = 527,472.14/819.35
  6. Step 6: Final answer
    x = 643.77

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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.