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Finding the Fourth Proportional to 664.60, 996.90 and 421.29

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Solution

The fourth proportional to 664.60, 996.90 and 421.29 is: 631.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.60 : 996.90 = 421.29 : x
  2. Step 2: Convert to fraction form
    664.60/996.90 = 421.29/x
  3. Step 3: Cross multiply
    664.60x = 996.90 × 421.29
  4. Step 4: Simplify right side
    664.60x = 419,984.00
  5. Step 5: Solve for x
    x = 419,984.00/664.60
  6. Step 6: Final answer
    x = 631.94

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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.