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Finding the Fourth Proportional to 819.79, 1,229.84 and 402.90

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Solution

The fourth proportional to 819.79, 1,229.84 and 402.90 is: 604.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.79 : 1,229.84 = 402.90 : x
  2. Step 2: Convert to fraction form
    819.79/1,229.84 = 402.90/x
  3. Step 3: Cross multiply
    819.79x = 1,229.84 × 402.90
  4. Step 4: Simplify right side
    819.79x = 495,502.54
  5. Step 5: Solve for x
    x = 495,502.54/819.79
  6. Step 6: Final answer
    x = 604.43

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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.