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Finding the Fourth Proportional to 489.98, 676.11 and 280.20

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Solution

The fourth proportional to 489.98, 676.11 and 280.20 is: 386.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.98 : 676.11 = 280.20 : x
  2. Step 2: Convert to fraction form
    489.98/676.11 = 280.20/x
  3. Step 3: Cross multiply
    489.98x = 676.11 × 280.20
  4. Step 4: Simplify right side
    489.98x = 189,446.02
  5. Step 5: Solve for x
    x = 189,446.02/489.98
  6. Step 6: Final answer
    x = 386.64

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.