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Finding the Fourth Proportional to 372.11, 557.96 and 128.57

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Solution

The fourth proportional to 372.11, 557.96 and 128.57 is: 192.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    372.11 : 557.96 = 128.57 : x
  2. Step 2: Convert to fraction form
    372.11/557.96 = 128.57/x
  3. Step 3: Cross multiply
    372.11x = 557.96 × 128.57
  4. Step 4: Simplify right side
    372.11x = 71,733.48
  5. Step 5: Solve for x
    x = 71,733.48/372.11
  6. Step 6: Final answer
    x = 192.78

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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.