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Finding the Fourth Proportional to 138.70, 206.69 and 126.55

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Solution

The fourth proportional to 138.70, 206.69 and 126.55 is: 188.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.70 : 206.69 = 126.55 : x
  2. Step 2: Convert to fraction form
    138.70/206.69 = 126.55/x
  3. Step 3: Cross multiply
    138.70x = 206.69 × 126.55
  4. Step 4: Simplify right side
    138.70x = 26,156.62
  5. Step 5: Solve for x
    x = 26,156.62/138.70
  6. Step 6: Final answer
    x = 188.58

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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.