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Finding the Fourth Proportional to 862.91, 1,190.87 and 489.90

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Solution

The fourth proportional to 862.91, 1,190.87 and 489.90 is: 676.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    862.91 : 1,190.87 = 489.90 : x
  2. Step 2: Convert to fraction form
    862.91/1,190.87 = 489.90/x
  3. Step 3: Cross multiply
    862.91x = 1,190.87 × 489.90
  4. Step 4: Simplify right side
    862.91x = 583,410.47
  5. Step 5: Solve for x
    x = 583,410.47/862.91
  6. Step 6: Final answer
    x = 676.10

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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.