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Finding the Fourth Proportional to 686.20, 1,029.84 and 361.68

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Solution

The fourth proportional to 686.20, 1,029.84 and 361.68 is: 542.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.20 : 1,029.84 = 361.68 : x
  2. Step 2: Convert to fraction form
    686.20/1,029.84 = 361.68/x
  3. Step 3: Cross multiply
    686.20x = 1,029.84 × 361.68
  4. Step 4: Simplify right side
    686.20x = 372,472.53
  5. Step 5: Solve for x
    x = 372,472.53/686.20
  6. Step 6: Final answer
    x = 542.80

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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.