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Finding the Fourth Proportional to 664.50, 917.21 and 490.35

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Solution

The fourth proportional to 664.50, 917.21 and 490.35 is: 676.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.50 : 917.21 = 490.35 : x
  2. Step 2: Convert to fraction form
    664.50/917.21 = 490.35/x
  3. Step 3: Cross multiply
    664.50x = 917.21 × 490.35
  4. Step 4: Simplify right side
    664.50x = 449,753.92
  5. Step 5: Solve for x
    x = 449,753.92/664.50
  6. Step 6: Final answer
    x = 676.83

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.