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Finding the Fourth Proportional to 686.15, 1,029.09 and 339.12

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Solution

The fourth proportional to 686.15, 1,029.09 and 339.12 is: 508.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.15 : 1,029.09 = 339.12 : x
  2. Step 2: Convert to fraction form
    686.15/1,029.09 = 339.12/x
  3. Step 3: Cross multiply
    686.15x = 1,029.09 × 339.12
  4. Step 4: Simplify right side
    686.15x = 348,984.36
  5. Step 5: Solve for x
    x = 348,984.36/686.15
  6. Step 6: Final answer
    x = 508.61

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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.