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Finding the Fourth Proportional to 939.20, 1,408.34 and 345.97

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Solution

The fourth proportional to 939.20, 1,408.34 and 345.97 is: 518.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    939.20 : 1,408.34 = 345.97 : x
  2. Step 2: Convert to fraction form
    939.20/1,408.34 = 345.97/x
  3. Step 3: Cross multiply
    939.20x = 1,408.34 × 345.97
  4. Step 4: Simplify right side
    939.20x = 487,244.07
  5. Step 5: Solve for x
    x = 487,244.07/939.20
  6. Step 6: Final answer
    x = 518.79

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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.