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Finding the Fourth Proportional to 686.30, 1,028.10 and 411.58

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Solution

The fourth proportional to 686.30, 1,028.10 and 411.58 is: 616.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.30 : 1,028.10 = 411.58 : x
  2. Step 2: Convert to fraction form
    686.30/1,028.10 = 411.58/x
  3. Step 3: Cross multiply
    686.30x = 1,028.10 × 411.58
  4. Step 4: Simplify right side
    686.30x = 423,140.26
  5. Step 5: Solve for x
    x = 423,140.26/686.30
  6. Step 6: Final answer
    x = 616.55

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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.