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Finding the Fourth Proportional to 84.87, 127.17 and 39.15

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Solution

The fourth proportional to 84.87, 127.17 and 39.15 is: 58.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.87 : 127.17 = 39.15 : x
  2. Step 2: Convert to fraction form
    84.87/127.17 = 39.15/x
  3. Step 3: Cross multiply
    84.87x = 127.17 × 39.15
  4. Step 4: Simplify right side
    84.87x = 4,978.71
  5. Step 5: Solve for x
    x = 4,978.71/84.87
  6. Step 6: Final answer
    x = 58.66

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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.