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Finding the Fourth Proportional to 521.46, 782.20 and 489.78

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Solution

The fourth proportional to 521.46, 782.20 and 489.78 is: 734.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.46 : 782.20 = 489.78 : x
  2. Step 2: Convert to fraction form
    521.46/782.20 = 489.78/x
  3. Step 3: Cross multiply
    521.46x = 782.20 × 489.78
  4. Step 4: Simplify right side
    521.46x = 383,105.92
  5. Step 5: Solve for x
    x = 383,105.92/521.46
  6. Step 6: Final answer
    x = 734.68

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Double scale
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Similar ratio
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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.