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Finding the Fourth Proportional to 198.87, 298.42 and 77.15

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Solution

The fourth proportional to 198.87, 298.42 and 77.15 is: 115.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.87 : 298.42 = 77.15 : x
  2. Step 2: Convert to fraction form
    198.87/298.42 = 77.15/x
  3. Step 3: Cross multiply
    198.87x = 298.42 × 77.15
  4. Step 4: Simplify right side
    198.87x = 23,021.42
  5. Step 5: Solve for x
    x = 23,021.42/198.87
  6. Step 6: Final answer
    x = 115.76

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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.