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Finding the Fourth Proportional to 805.41, 1,208.21 and 311.81

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Solution

The fourth proportional to 805.41, 1,208.21 and 311.81 is: 467.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.41 : 1,208.21 = 311.81 : x
  2. Step 2: Convert to fraction form
    805.41/1,208.21 = 311.81/x
  3. Step 3: Cross multiply
    805.41x = 1,208.21 × 311.81
  4. Step 4: Simplify right side
    805.41x = 376,724.36
  5. Step 5: Solve for x
    x = 376,724.36/805.41
  6. Step 6: Final answer
    x = 467.74

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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.