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Finding the Fourth Proportional to 489.66, 735.12 and 428.82

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Solution

The fourth proportional to 489.66, 735.12 and 428.82 is: 643.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.66 : 735.12 = 428.82 : x
  2. Step 2: Convert to fraction form
    489.66/735.12 = 428.82/x
  3. Step 3: Cross multiply
    489.66x = 735.12 × 428.82
  4. Step 4: Simplify right side
    489.66x = 315,234.16
  5. Step 5: Solve for x
    x = 315,234.16/489.66
  6. Step 6: Final answer
    x = 643.78

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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.