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Finding the Fourth Proportional to 426.49, 639.72 and 209.89

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Solution

The fourth proportional to 426.49, 639.72 and 209.89 is: 314.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.49 : 639.72 = 209.89 : x
  2. Step 2: Convert to fraction form
    426.49/639.72 = 209.89/x
  3. Step 3: Cross multiply
    426.49x = 639.72 × 209.89
  4. Step 4: Simplify right side
    426.49x = 134,270.83
  5. Step 5: Solve for x
    x = 134,270.83/426.49
  6. Step 6: Final answer
    x = 314.83

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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.