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Finding the Fourth Proportional to 686.67, 1,029.20 and 397.50

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Solution

The fourth proportional to 686.67, 1,029.20 and 397.50 is: 595.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.67 : 1,029.20 = 397.50 : x
  2. Step 2: Convert to fraction form
    686.67/1,029.20 = 397.50/x
  3. Step 3: Cross multiply
    686.67x = 1,029.20 × 397.50
  4. Step 4: Simplify right side
    686.67x = 409,105.01
  5. Step 5: Solve for x
    x = 409,105.01/686.67
  6. Step 6: Final answer
    x = 595.78

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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.