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Finding the Fourth Proportional to 814, 1,221.12 and 380.92

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Solution

The fourth proportional to 814, 1,221.12 and 380.92 is: 571.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    814 : 1,221.12 = 380.92 : x
  2. Step 2: Convert to fraction form
    814/1,221.12 = 380.92/x
  3. Step 3: Cross multiply
    814x = 1,221.12 × 380.92
  4. Step 4: Simplify right side
    814x = 465,149.03
  5. Step 5: Solve for x
    x = 465,149.03/814
  6. Step 6: Final answer
    x = 571.44

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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.