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Finding the Fourth Proportional to 686.21, 1,027.46 and 411.91

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Solution

The fourth proportional to 686.21, 1,027.46 and 411.91 is: 616.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.21 : 1,027.46 = 411.91 : x
  2. Step 2: Convert to fraction form
    686.21/1,027.46 = 411.91/x
  3. Step 3: Cross multiply
    686.21x = 1,027.46 × 411.91
  4. Step 4: Simplify right side
    686.21x = 423,219.51
  5. Step 5: Solve for x
    x = 423,219.51/686.21
  6. Step 6: Final answer
    x = 616.75

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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.