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Finding the Fourth Proportional to 426.02, 638.89 and 209.57

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Solution

The fourth proportional to 426.02, 638.89 and 209.57 is: 314.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.02 : 638.89 = 209.57 : x
  2. Step 2: Convert to fraction form
    426.02/638.89 = 209.57/x
  3. Step 3: Cross multiply
    426.02x = 638.89 × 209.57
  4. Step 4: Simplify right side
    426.02x = 133,888.46
  5. Step 5: Solve for x
    x = 133,888.46/426.02
  6. Step 6: Final answer
    x = 314.28

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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.