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Finding the Fourth Proportional to 686.42, 1,028.82 and 397.26

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Solution

The fourth proportional to 686.42, 1,028.82 and 397.26 is: 595.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.42 : 1,028.82 = 397.26 : x
  2. Step 2: Convert to fraction form
    686.42/1,028.82 = 397.26/x
  3. Step 3: Cross multiply
    686.42x = 1,028.82 × 397.26
  4. Step 4: Simplify right side
    686.42x = 408,709.03
  5. Step 5: Solve for x
    x = 408,709.03/686.42
  6. Step 6: Final answer
    x = 595.42

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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.