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Finding the Fourth Proportional to 142.87, 197.07 and 87.61

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Solution

The fourth proportional to 142.87, 197.07 and 87.61 is: 120.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.87 : 197.07 = 87.61 : x
  2. Step 2: Convert to fraction form
    142.87/197.07 = 87.61/x
  3. Step 3: Cross multiply
    142.87x = 197.07 × 87.61
  4. Step 4: Simplify right side
    142.87x = 17,265.30
  5. Step 5: Solve for x
    x = 17,265.30/142.87
  6. Step 6: Final answer
    x = 120.85

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.