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Finding the Fourth Proportional to 426.28, 638.97 and 209.41

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Solution

The fourth proportional to 426.28, 638.97 and 209.41 is: 313.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.28 : 638.97 = 209.41 : x
  2. Step 2: Convert to fraction form
    426.28/638.97 = 209.41/x
  3. Step 3: Cross multiply
    426.28x = 638.97 × 209.41
  4. Step 4: Simplify right side
    426.28x = 133,806.71
  5. Step 5: Solve for x
    x = 133,806.71/426.28
  6. Step 6: Final answer
    x = 313.89

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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.