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Finding the Fourth Proportional to 138.38, 207.42 and 112.86

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Solution

The fourth proportional to 138.38, 207.42 and 112.86 is: 169.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.38 : 207.42 = 112.86 : x
  2. Step 2: Convert to fraction form
    138.38/207.42 = 112.86/x
  3. Step 3: Cross multiply
    138.38x = 207.42 × 112.86
  4. Step 4: Simplify right side
    138.38x = 23,409.42
  5. Step 5: Solve for x
    x = 23,409.42/138.38
  6. Step 6: Final answer
    x = 169.17

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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.