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Finding the Fourth Proportional to 805.31, 1,208.13 and 311.70

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Solution

The fourth proportional to 805.31, 1,208.13 and 311.70 is: 467.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.31 : 1,208.13 = 311.70 : x
  2. Step 2: Convert to fraction form
    805.31/1,208.13 = 311.70/x
  3. Step 3: Cross multiply
    805.31x = 1,208.13 × 311.70
  4. Step 4: Simplify right side
    805.31x = 376,572.56
  5. Step 5: Solve for x
    x = 376,572.56/805.31
  6. Step 6: Final answer
    x = 467.61

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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.