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Finding the Fourth Proportional to 426.08, 639.21 and 206.86

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Solution

The fourth proportional to 426.08, 639.21 and 206.86 is: 310.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.08 : 639.21 = 206.86 : x
  2. Step 2: Convert to fraction form
    426.08/639.21 = 206.86/x
  3. Step 3: Cross multiply
    426.08x = 639.21 × 206.86
  4. Step 4: Simplify right side
    426.08x = 132,226.98
  5. Step 5: Solve for x
    x = 132,226.98/426.08
  6. Step 6: Final answer
    x = 310.33

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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.