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Finding the Fourth Proportional to 80.31, 120.39 and 49.80

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Solution

The fourth proportional to 80.31, 120.39 and 49.80 is: 74.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.31 : 120.39 = 49.80 : x
  2. Step 2: Convert to fraction form
    80.31/120.39 = 49.80/x
  3. Step 3: Cross multiply
    80.31x = 120.39 × 49.80
  4. Step 4: Simplify right side
    80.31x = 5,995.42
  5. Step 5: Solve for x
    x = 5,995.42/80.31
  6. Step 6: Final answer
    x = 74.65

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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.