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Finding the Fourth Proportional to 138.13, 206.66 and 120.88

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Solution

The fourth proportional to 138.13, 206.66 and 120.88 is: 180.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.13 : 206.66 = 120.88 : x
  2. Step 2: Convert to fraction form
    138.13/206.66 = 120.88/x
  3. Step 3: Cross multiply
    138.13x = 206.66 × 120.88
  4. Step 4: Simplify right side
    138.13x = 24,981.06
  5. Step 5: Solve for x
    x = 24,981.06/138.13
  6. Step 6: Final answer
    x = 180.85

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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.