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Finding the Fourth Proportional to 138.80, 207.89 and 57.39

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Solution

The fourth proportional to 138.80, 207.89 and 57.39 is: 85.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.80 : 207.89 = 57.39 : x
  2. Step 2: Convert to fraction form
    138.80/207.89 = 57.39/x
  3. Step 3: Cross multiply
    138.80x = 207.89 × 57.39
  4. Step 4: Simplify right side
    138.80x = 11,930.52
  5. Step 5: Solve for x
    x = 11,930.52/138.80
  6. Step 6: Final answer
    x = 85.96

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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.