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Finding the Fourth Proportional to 396.80, 547.20 and 309.44

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Solution

The fourth proportional to 396.80, 547.20 and 309.44 is: 426.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    396.80 : 547.20 = 309.44 : x
  2. Step 2: Convert to fraction form
    396.80/547.20 = 309.44/x
  3. Step 3: Cross multiply
    396.80x = 547.20 × 309.44
  4. Step 4: Simplify right side
    396.80x = 169,325.57
  5. Step 5: Solve for x
    x = 169,325.57/396.80
  6. Step 6: Final answer
    x = 426.73

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.