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Finding the Fourth Proportional to 686.07, 1,028.68 and 338.64

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Solution

The fourth proportional to 686.07, 1,028.68 and 338.64 is: 507.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.07 : 1,028.68 = 338.64 : x
  2. Step 2: Convert to fraction form
    686.07/1,028.68 = 338.64/x
  3. Step 3: Cross multiply
    686.07x = 1,028.68 × 338.64
  4. Step 4: Simplify right side
    686.07x = 348,352.20
  5. Step 5: Solve for x
    x = 348,352.20/686.07
  6. Step 6: Final answer
    x = 507.75

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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.