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Finding the Fourth Proportional to 138.14, 207.26 and 86.91

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Solution

The fourth proportional to 138.14, 207.26 and 86.91 is: 130.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.14 : 207.26 = 86.91 : x
  2. Step 2: Convert to fraction form
    138.14/207.26 = 86.91/x
  3. Step 3: Cross multiply
    138.14x = 207.26 × 86.91
  4. Step 4: Simplify right side
    138.14x = 18,012.08
  5. Step 5: Solve for x
    x = 18,012.08/138.14
  6. Step 6: Final answer
    x = 130.39

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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.