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Finding the Fourth Proportional to 814.85, 1,221.57 and 327.78

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Solution

The fourth proportional to 814.85, 1,221.57 and 327.78 is: 491.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.85 : 1,221.57 = 327.78 : x
  2. Step 2: Convert to fraction form
    814.85/1,221.57 = 327.78/x
  3. Step 3: Cross multiply
    814.85x = 1,221.57 × 327.78
  4. Step 4: Simplify right side
    814.85x = 400,406.21
  5. Step 5: Solve for x
    x = 400,406.21/814.85
  6. Step 6: Final answer
    x = 491.39

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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.