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Finding the Fourth Proportional to 402.62, 603.89 and 128.91

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Solution

The fourth proportional to 402.62, 603.89 and 128.91 is: 193.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.62 : 603.89 = 128.91 : x
  2. Step 2: Convert to fraction form
    402.62/603.89 = 128.91/x
  3. Step 3: Cross multiply
    402.62x = 603.89 × 128.91
  4. Step 4: Simplify right side
    402.62x = 77,847.78
  5. Step 5: Solve for x
    x = 77,847.78/402.62
  6. Step 6: Final answer
    x = 193.35

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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.