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Finding the Fourth Proportional to 425.91, 638.87 and 280.58

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Solution

The fourth proportional to 425.91, 638.87 and 280.58 is: 420.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.91 : 638.87 = 280.58 : x
  2. Step 2: Convert to fraction form
    425.91/638.87 = 280.58/x
  3. Step 3: Cross multiply
    425.91x = 638.87 × 280.58
  4. Step 4: Simplify right side
    425.91x = 179,254.34
  5. Step 5: Solve for x
    x = 179,254.34/425.91
  6. Step 6: Final answer
    x = 420.87

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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.