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Finding the Fourth Proportional to 127.38, 190.72 and 86.61

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Solution

The fourth proportional to 127.38, 190.72 and 86.61 is: 129.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.38 : 190.72 = 86.61 : x
  2. Step 2: Convert to fraction form
    127.38/190.72 = 86.61/x
  3. Step 3: Cross multiply
    127.38x = 190.72 × 86.61
  4. Step 4: Simplify right side
    127.38x = 16,518.26
  5. Step 5: Solve for x
    x = 16,518.26/127.38
  6. Step 6: Final answer
    x = 129.68

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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.