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Finding the Fourth Proportional to 686.05, 1,028.32 and 338.87

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Solution

The fourth proportional to 686.05, 1,028.32 and 338.87 is: 507.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.05 : 1,028.32 = 338.87 : x
  2. Step 2: Convert to fraction form
    686.05/1,028.32 = 338.87/x
  3. Step 3: Cross multiply
    686.05x = 1,028.32 × 338.87
  4. Step 4: Simplify right side
    686.05x = 348,466.80
  5. Step 5: Solve for x
    x = 348,466.80/686.05
  6. Step 6: Final answer
    x = 507.93

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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.