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Finding the Fourth Proportional to 80.20, 120.39 and 56.20

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Solution

The fourth proportional to 80.20, 120.39 and 56.20 is: 84.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.20 : 120.39 = 56.20 : x
  2. Step 2: Convert to fraction form
    80.20/120.39 = 56.20/x
  3. Step 3: Cross multiply
    80.20x = 120.39 × 56.20
  4. Step 4: Simplify right side
    80.20x = 6,765.92
  5. Step 5: Solve for x
    x = 6,765.92/80.20
  6. Step 6: Final answer
    x = 84.36

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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.