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Finding the Fourth Proportional to 688.20, 1,028.12 and 684.96

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Solution

The fourth proportional to 688.20, 1,028.12 and 684.96 is: 1,023.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.20 : 1,028.12 = 684.96 : x
  2. Step 2: Convert to fraction form
    688.20/1,028.12 = 684.96/x
  3. Step 3: Cross multiply
    688.20x = 1,028.12 × 684.96
  4. Step 4: Simplify right side
    688.20x = 704,221.08
  5. Step 5: Solve for x
    x = 704,221.08/688.20
  6. Step 6: Final answer
    x = 1,023.28

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.