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Finding the Fourth Proportional to 814.38, 1,220.64 and 402.90

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Solution

The fourth proportional to 814.38, 1,220.64 and 402.90 is: 603.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.38 : 1,220.64 = 402.90 : x
  2. Step 2: Convert to fraction form
    814.38/1,220.64 = 402.90/x
  3. Step 3: Cross multiply
    814.38x = 1,220.64 × 402.90
  4. Step 4: Simplify right side
    814.38x = 491,795.86
  5. Step 5: Solve for x
    x = 491,795.86/814.38
  6. Step 6: Final answer
    x = 603.89

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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.