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Finding the Fourth Proportional to 686.83, 1,029.28 and 378.83

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Solution

The fourth proportional to 686.83, 1,029.28 and 378.83 is: 567.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.83 : 1,029.28 = 378.83 : x
  2. Step 2: Convert to fraction form
    686.83/1,029.28 = 378.83/x
  3. Step 3: Cross multiply
    686.83x = 1,029.28 × 378.83
  4. Step 4: Simplify right side
    686.83x = 389,916.05
  5. Step 5: Solve for x
    x = 389,916.05/686.83
  6. Step 6: Final answer
    x = 567.71

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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.