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Finding the Fourth Proportional to 686.20, 946.93 and 391.44

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Solution

The fourth proportional to 686.20, 946.93 and 391.44 is: 540.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.20 : 946.93 = 391.44 : x
  2. Step 2: Convert to fraction form
    686.20/946.93 = 391.44/x
  3. Step 3: Cross multiply
    686.20x = 946.93 × 391.44
  4. Step 4: Simplify right side
    686.20x = 370,665.30
  5. Step 5: Solve for x
    x = 370,665.30/686.20
  6. Step 6: Final answer
    x = 540.17

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.