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Finding the Fourth Proportional to 814.20, 1,221.78 and 327.18

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Solution

The fourth proportional to 814.20, 1,221.78 and 327.18 is: 490.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.20 : 1,221.78 = 327.18 : x
  2. Step 2: Convert to fraction form
    814.20/1,221.78 = 327.18/x
  3. Step 3: Cross multiply
    814.20x = 1,221.78 × 327.18
  4. Step 4: Simplify right side
    814.20x = 399,741.98
  5. Step 5: Solve for x
    x = 399,741.98/814.20
  6. Step 6: Final answer
    x = 490.96

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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.