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Finding the Fourth Proportional to 138.90, 208.35 and 115.82

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Solution

The fourth proportional to 138.90, 208.35 and 115.82 is: 173.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.90 : 208.35 = 115.82 : x
  2. Step 2: Convert to fraction form
    138.90/208.35 = 115.82/x
  3. Step 3: Cross multiply
    138.90x = 208.35 × 115.82
  4. Step 4: Simplify right side
    138.90x = 24,131.10
  5. Step 5: Solve for x
    x = 24,131.10/138.90
  6. Step 6: Final answer
    x = 173.73

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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.