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Finding the Fourth Proportional to 686.06, 1,028.41 and 321.11

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Solution

The fourth proportional to 686.06, 1,028.41 and 321.11 is: 481.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.06 : 1,028.41 = 321.11 : x
  2. Step 2: Convert to fraction form
    686.06/1,028.41 = 321.11/x
  3. Step 3: Cross multiply
    686.06x = 1,028.41 × 321.11
  4. Step 4: Simplify right side
    686.06x = 330,226.79
  5. Step 5: Solve for x
    x = 330,226.79/686.06
  6. Step 6: Final answer
    x = 481.34

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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.