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Finding the Fourth Proportional to 138.41, 207.10 and 85.46

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Solution

The fourth proportional to 138.41, 207.10 and 85.46 is: 127.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.41 : 207.10 = 85.46 : x
  2. Step 2: Convert to fraction form
    138.41/207.10 = 85.46/x
  3. Step 3: Cross multiply
    138.41x = 207.10 × 85.46
  4. Step 4: Simplify right side
    138.41x = 17,697.52
  5. Step 5: Solve for x
    x = 17,697.52/138.41
  6. Step 6: Final answer
    x = 127.86

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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.