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Finding the Fourth Proportional to 426.47, 639.89 and 206.97

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Solution

The fourth proportional to 426.47, 639.89 and 206.97 is: 310.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.47 : 639.89 = 206.97 : x
  2. Step 2: Convert to fraction form
    426.47/639.89 = 206.97/x
  3. Step 3: Cross multiply
    426.47x = 639.89 × 206.97
  4. Step 4: Simplify right side
    426.47x = 132,437.00
  5. Step 5: Solve for x
    x = 132,437.00/426.47
  6. Step 6: Final answer
    x = 310.55

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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.