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Finding the Fourth Proportional to 138.11, 206.99 and 56.87

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Solution

The fourth proportional to 138.11, 206.99 and 56.87 is: 85.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.11 : 206.99 = 56.87 : x
  2. Step 2: Convert to fraction form
    138.11/206.99 = 56.87/x
  3. Step 3: Cross multiply
    138.11x = 206.99 × 56.87
  4. Step 4: Simplify right side
    138.11x = 11,770.20
  5. Step 5: Solve for x
    x = 11,770.20/138.11
  6. Step 6: Final answer
    x = 85.23

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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.