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Finding the Fourth Proportional to 138.31, 207.48 and 40.81

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Solution

The fourth proportional to 138.31, 207.48 and 40.81 is: 61.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.31 : 207.48 = 40.81 : x
  2. Step 2: Convert to fraction form
    138.31/207.48 = 40.81/x
  3. Step 3: Cross multiply
    138.31x = 207.48 × 40.81
  4. Step 4: Simplify right side
    138.31x = 8,467.05
  5. Step 5: Solve for x
    x = 8,467.05/138.31
  6. Step 6: Final answer
    x = 61.22

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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.