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Finding the Fourth Proportional to 125.20, 187.62 and 86.60

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Solution

The fourth proportional to 125.20, 187.62 and 86.60 is: 129.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    125.20 : 187.62 = 86.60 : x
  2. Step 2: Convert to fraction form
    125.20/187.62 = 86.60/x
  3. Step 3: Cross multiply
    125.20x = 187.62 × 86.60
  4. Step 4: Simplify right side
    125.20x = 16,247.89
  5. Step 5: Solve for x
    x = 16,247.89/125.20
  6. Step 6: Final answer
    x = 129.78

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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.