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Finding the Fourth Proportional to 814.54, 1,221.01 and 521.21

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Solution

The fourth proportional to 814.54, 1,221.01 and 521.21 is: 781.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.54 : 1,221.01 = 521.21 : x
  2. Step 2: Convert to fraction form
    814.54/1,221.01 = 521.21/x
  3. Step 3: Cross multiply
    814.54x = 1,221.01 × 521.21
  4. Step 4: Simplify right side
    814.54x = 636,403.14
  5. Step 5: Solve for x
    x = 636,403.14/814.54
  6. Step 6: Final answer
    x = 781.30

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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.