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Finding the Fourth Proportional to 198.85, 298.28 and 77.09

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Solution

The fourth proportional to 198.85, 298.28 and 77.09 is: 115.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.85 : 298.28 = 77.09 : x
  2. Step 2: Convert to fraction form
    198.85/298.28 = 77.09/x
  3. Step 3: Cross multiply
    198.85x = 298.28 × 77.09
  4. Step 4: Simplify right side
    198.85x = 22,995.15
  5. Step 5: Solve for x
    x = 22,995.15/198.85
  6. Step 6: Final answer
    x = 115.64

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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.