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Finding the Fourth Proportional to 138.12, 207.63 and 77.37

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Solution

The fourth proportional to 138.12, 207.63 and 77.37 is: 116.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.12 : 207.63 = 77.37 : x
  2. Step 2: Convert to fraction form
    138.12/207.63 = 77.37/x
  3. Step 3: Cross multiply
    138.12x = 207.63 × 77.37
  4. Step 4: Simplify right side
    138.12x = 16,064.33
  5. Step 5: Solve for x
    x = 16,064.33/138.12
  6. Step 6: Final answer
    x = 116.31

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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.