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Finding the Fourth Proportional to 686.57, 1,028.64 and 671.99

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Solution

The fourth proportional to 686.57, 1,028.64 and 671.99 is: 1,006.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.57 : 1,028.64 = 671.99 : x
  2. Step 2: Convert to fraction form
    686.57/1,028.64 = 671.99/x
  3. Step 3: Cross multiply
    686.57x = 1,028.64 × 671.99
  4. Step 4: Simplify right side
    686.57x = 691,235.79
  5. Step 5: Solve for x
    x = 691,235.79/686.57
  6. Step 6: Final answer
    x = 1,006.80

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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.