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Finding the Fourth Proportional to 489.80, 733.92 and 391.78

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Solution

The fourth proportional to 489.80, 733.92 and 391.78 is: 587.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.80 : 733.92 = 391.78 : x
  2. Step 2: Convert to fraction form
    489.80/733.92 = 391.78/x
  3. Step 3: Cross multiply
    489.80x = 733.92 × 391.78
  4. Step 4: Simplify right side
    489.80x = 287,535.18
  5. Step 5: Solve for x
    x = 287,535.18/489.80
  6. Step 6: Final answer
    x = 587.05

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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.