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Finding the Fourth Proportional to 138.66, 206.85 and 125.70

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Solution

The fourth proportional to 138.66, 206.85 and 125.70 is: 187.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.66 : 206.85 = 125.70 : x
  2. Step 2: Convert to fraction form
    138.66/206.85 = 125.70/x
  3. Step 3: Cross multiply
    138.66x = 206.85 × 125.70
  4. Step 4: Simplify right side
    138.66x = 26,001.05
  5. Step 5: Solve for x
    x = 26,001.05/138.66
  6. Step 6: Final answer
    x = 187.52

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.