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Finding the Fourth Proportional to 489.72, 735.78 and 428.96

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Solution

The fourth proportional to 489.72, 735.78 and 428.96 is: 644.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.72 : 735.78 = 428.96 : x
  2. Step 2: Convert to fraction form
    489.72/735.78 = 428.96/x
  3. Step 3: Cross multiply
    489.72x = 735.78 × 428.96
  4. Step 4: Simplify right side
    489.72x = 315,620.19
  5. Step 5: Solve for x
    x = 315,620.19/489.72
  6. Step 6: Final answer
    x = 644.49

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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.