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Finding the Fourth Proportional to 686.41, 1,029.49 and 438.89

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Solution

The fourth proportional to 686.41, 1,029.49 and 438.89 is: 658.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.41 : 1,029.49 = 438.89 : x
  2. Step 2: Convert to fraction form
    686.41/1,029.49 = 438.89/x
  3. Step 3: Cross multiply
    686.41x = 1,029.49 × 438.89
  4. Step 4: Simplify right side
    686.41x = 451,826.62
  5. Step 5: Solve for x
    x = 451,826.62/686.41
  6. Step 6: Final answer
    x = 658.25

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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.