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Finding the Fourth Proportional to 819.81, 1,229.97 and 490.70

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Solution

The fourth proportional to 819.81, 1,229.97 and 490.70 is: 736.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.81 : 1,229.97 = 490.70 : x
  2. Step 2: Convert to fraction form
    819.81/1,229.97 = 490.70/x
  3. Step 3: Cross multiply
    819.81x = 1,229.97 × 490.70
  4. Step 4: Simplify right side
    819.81x = 603,540.13
  5. Step 5: Solve for x
    x = 603,540.13/819.81
  6. Step 6: Final answer
    x = 736.20

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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.