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Finding the Fourth Proportional to 402.89, 604.13 and 128.90

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Solution

The fourth proportional to 402.89, 604.13 and 128.90 is: 193.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.89 : 604.13 = 128.90 : x
  2. Step 2: Convert to fraction form
    402.89/604.13 = 128.90/x
  3. Step 3: Cross multiply
    402.89x = 604.13 × 128.90
  4. Step 4: Simplify right side
    402.89x = 77,868.69
  5. Step 5: Solve for x
    x = 77,868.69/402.89
  6. Step 6: Final answer
    x = 193.28

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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.