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Finding the Fourth Proportional to 402.64, 604.06 and 128.72

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Solution

The fourth proportional to 402.64, 604.06 and 128.72 is: 193.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.64 : 604.06 = 128.72 : x
  2. Step 2: Convert to fraction form
    402.64/604.06 = 128.72/x
  3. Step 3: Cross multiply
    402.64x = 604.06 × 128.72
  4. Step 4: Simplify right side
    402.64x = 77,755.79
  5. Step 5: Solve for x
    x = 77,755.79/402.64
  6. Step 6: Final answer
    x = 193.12

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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.