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Finding the Fourth Proportional to 819.11, 1,129.61 and 609.80

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Solution

The fourth proportional to 819.11, 1,129.61 and 609.80 is: 840.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.11 : 1,129.61 = 609.80 : x
  2. Step 2: Convert to fraction form
    819.11/1,129.61 = 609.80/x
  3. Step 3: Cross multiply
    819.11x = 1,129.61 × 609.80
  4. Step 4: Simplify right side
    819.11x = 688,827.48
  5. Step 5: Solve for x
    x = 688,827.48/819.11
  6. Step 6: Final answer
    x = 840.95

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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.