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Finding the Fourth Proportional to 664.89, 996.43 and 420.98

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Solution

The fourth proportional to 664.89, 996.43 and 420.98 is: 630.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.89 : 996.43 = 420.98 : x
  2. Step 2: Convert to fraction form
    664.89/996.43 = 420.98/x
  3. Step 3: Cross multiply
    664.89x = 996.43 × 420.98
  4. Step 4: Simplify right side
    664.89x = 419,476.28
  5. Step 5: Solve for x
    x = 419,476.28/664.89
  6. Step 6: Final answer
    x = 630.89

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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.