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Finding the Fourth Proportional to 402.80, 604.29 and 128.87

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Solution

The fourth proportional to 402.80, 604.29 and 128.87 is: 193.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.80 : 604.29 = 128.87 : x
  2. Step 2: Convert to fraction form
    402.80/604.29 = 128.87/x
  3. Step 3: Cross multiply
    402.80x = 604.29 × 128.87
  4. Step 4: Simplify right side
    402.80x = 77,874.85
  5. Step 5: Solve for x
    x = 77,874.85/402.80
  6. Step 6: Final answer
    x = 193.33

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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.