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Finding the Fourth Proportional to 686.80, 1,028.04 and 491.17

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Solution

The fourth proportional to 686.80, 1,028.04 and 491.17 is: 735.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.80 : 1,028.04 = 491.17 : x
  2. Step 2: Convert to fraction form
    686.80/1,028.04 = 491.17/x
  3. Step 3: Cross multiply
    686.80x = 1,028.04 × 491.17
  4. Step 4: Simplify right side
    686.80x = 504,942.41
  5. Step 5: Solve for x
    x = 504,942.41/686.80
  6. Step 6: Final answer
    x = 735.21

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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.