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Finding the Fourth Proportional to 686.48, 1,029.11 and 412.70

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Solution

The fourth proportional to 686.48, 1,029.11 and 412.70 is: 618.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.48 : 1,029.11 = 412.70 : x
  2. Step 2: Convert to fraction form
    686.48/1,029.11 = 412.70/x
  3. Step 3: Cross multiply
    686.48x = 1,029.11 × 412.70
  4. Step 4: Simplify right side
    686.48x = 424,706.49
  5. Step 5: Solve for x
    x = 424,706.49/686.48
  6. Step 6: Final answer
    x = 618.68

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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.