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Finding the Fourth Proportional to 137.77, 206.49 and 76.81

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Solution

The fourth proportional to 137.77, 206.49 and 76.81 is: 115.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.77 : 206.49 = 76.81 : x
  2. Step 2: Convert to fraction form
    137.77/206.49 = 76.81/x
  3. Step 3: Cross multiply
    137.77x = 206.49 × 76.81
  4. Step 4: Simplify right side
    137.77x = 15,860.50
  5. Step 5: Solve for x
    x = 15,860.50/137.77
  6. Step 6: Final answer
    x = 115.12

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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.