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Finding the Fourth Proportional to 138.62, 207.80 and 57.48

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Solution

The fourth proportional to 138.62, 207.80 and 57.48 is: 86.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.62 : 207.80 = 57.48 : x
  2. Step 2: Convert to fraction form
    138.62/207.80 = 57.48/x
  3. Step 3: Cross multiply
    138.62x = 207.80 × 57.48
  4. Step 4: Simplify right side
    138.62x = 11,944.34
  5. Step 5: Solve for x
    x = 11,944.34/138.62
  6. Step 6: Final answer
    x = 86.17

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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.