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Finding the Fourth Proportional to 686.91, 1,029.87 and 321.49

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Solution

The fourth proportional to 686.91, 1,029.87 and 321.49 is: 482.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.91 : 1,029.87 = 321.49 : x
  2. Step 2: Convert to fraction form
    686.91/1,029.87 = 321.49/x
  3. Step 3: Cross multiply
    686.91x = 1,029.87 × 321.49
  4. Step 4: Simplify right side
    686.91x = 331,096.64
  5. Step 5: Solve for x
    x = 331,096.64/686.91
  6. Step 6: Final answer
    x = 482.01

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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.