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Finding the Fourth Proportional to 137.70, 206.56 and 76.79

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Solution

The fourth proportional to 137.70, 206.56 and 76.79 is: 115.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.70 : 206.56 = 76.79 : x
  2. Step 2: Convert to fraction form
    137.70/206.56 = 76.79/x
  3. Step 3: Cross multiply
    137.70x = 206.56 × 76.79
  4. Step 4: Simplify right side
    137.70x = 15,860.98
  5. Step 5: Solve for x
    x = 15,860.98/137.70
  6. Step 6: Final answer
    x = 115.18

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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.