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Finding the Fourth Proportional to 426.28, 638.52 and 209.56

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Solution

The fourth proportional to 426.28, 638.52 and 209.56 is: 313.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.28 : 638.52 = 209.56 : x
  2. Step 2: Convert to fraction form
    426.28/638.52 = 209.56/x
  3. Step 3: Cross multiply
    426.28x = 638.52 × 209.56
  4. Step 4: Simplify right side
    426.28x = 133,808.25
  5. Step 5: Solve for x
    x = 133,808.25/426.28
  6. Step 6: Final answer
    x = 313.90

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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.