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Finding the Fourth Proportional to 686.38, 1,029.30 and 398.02

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Solution

The fourth proportional to 686.38, 1,029.30 and 398.02 is: 596.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.38 : 1,029.30 = 398.02 : x
  2. Step 2: Convert to fraction form
    686.38/1,029.30 = 398.02/x
  3. Step 3: Cross multiply
    686.38x = 1,029.30 × 398.02
  4. Step 4: Simplify right side
    686.38x = 409,681.99
  5. Step 5: Solve for x
    x = 409,681.99/686.38
  6. Step 6: Final answer
    x = 596.87

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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.