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Finding the Fourth Proportional to 131.87, 198.02 and 77.20

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Solution

The fourth proportional to 131.87, 198.02 and 77.20 is: 115.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.87 : 198.02 = 77.20 : x
  2. Step 2: Convert to fraction form
    131.87/198.02 = 77.20/x
  3. Step 3: Cross multiply
    131.87x = 198.02 × 77.20
  4. Step 4: Simplify right side
    131.87x = 15,286.84
  5. Step 5: Solve for x
    x = 15,286.84/131.87
  6. Step 6: Final answer
    x = 115.92

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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.