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Finding the Fourth Proportional to 408, 612 and 280.56

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Solution

The fourth proportional to 408, 612 and 280.56 is: 420.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    408 : 612 = 280.56 : x
  2. Step 2: Convert to fraction form
    408/612 = 280.56/x
  3. Step 3: Cross multiply
    408x = 612 × 280.56
  4. Step 4: Simplify right side
    408x = 171,702.72
  5. Step 5: Solve for x
    x = 171,702.72/408
  6. Step 6: Final answer
    x = 420.84

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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.