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Finding the Fourth Proportional to 512.30, 768.90 and 439.40

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Solution

The fourth proportional to 512.30, 768.90 and 439.40 is: 659.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    512.30 : 768.90 = 439.40 : x
  2. Step 2: Convert to fraction form
    512.30/768.90 = 439.40/x
  3. Step 3: Cross multiply
    512.30x = 768.90 × 439.40
  4. Step 4: Simplify right side
    512.30x = 337,854.66
  5. Step 5: Solve for x
    x = 337,854.66/512.30
  6. Step 6: Final answer
    x = 659.49

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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.