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Finding the Fourth Proportional to 814.42, 1,219.65 and 381.70

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Solution

The fourth proportional to 814.42, 1,219.65 and 381.70 is: 571.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.42 : 1,219.65 = 381.70 : x
  2. Step 2: Convert to fraction form
    814.42/1,219.65 = 381.70/x
  3. Step 3: Cross multiply
    814.42x = 1,219.65 × 381.70
  4. Step 4: Simplify right side
    814.42x = 465,540.41
  5. Step 5: Solve for x
    x = 465,540.41/814.42
  6. Step 6: Final answer
    x = 571.62

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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.