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Finding the Fourth Proportional to 809.55, 1,213.38 and 392.85

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Solution

The fourth proportional to 809.55, 1,213.38 and 392.85 is: 588.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.55 : 1,213.38 = 392.85 : x
  2. Step 2: Convert to fraction form
    809.55/1,213.38 = 392.85/x
  3. Step 3: Cross multiply
    809.55x = 1,213.38 × 392.85
  4. Step 4: Simplify right side
    809.55x = 476,676.33
  5. Step 5: Solve for x
    x = 476,676.33/809.55
  6. Step 6: Final answer
    x = 588.82

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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.