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Finding the Fourth Proportional to 138.19, 207.13 and 69.77

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Solution

The fourth proportional to 138.19, 207.13 and 69.77 is: 104.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.19 : 207.13 = 69.77 : x
  2. Step 2: Convert to fraction form
    138.19/207.13 = 69.77/x
  3. Step 3: Cross multiply
    138.19x = 207.13 × 69.77
  4. Step 4: Simplify right side
    138.19x = 14,451.80
  5. Step 5: Solve for x
    x = 14,451.80/138.19
  6. Step 6: Final answer
    x = 104.58

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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.