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Finding the Fourth Proportional to 814.50, 1,221.54 and 505.21

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Solution

The fourth proportional to 814.50, 1,221.54 and 505.21 is: 757.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.50 : 1,221.54 = 505.21 : x
  2. Step 2: Convert to fraction form
    814.50/1,221.54 = 505.21/x
  3. Step 3: Cross multiply
    814.50x = 1,221.54 × 505.21
  4. Step 4: Simplify right side
    814.50x = 617,134.22
  5. Step 5: Solve for x
    x = 617,134.22/814.50
  6. Step 6: Final answer
    x = 757.68

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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.