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Finding the Fourth Proportional to 821.36, 1,231.32 and 308

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Solution

The fourth proportional to 821.36, 1,231.32 and 308 is: 461.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.36 : 1,231.32 = 308 : x
  2. Step 2: Convert to fraction form
    821.36/1,231.32 = 308/x
  3. Step 3: Cross multiply
    821.36x = 1,231.32 × 308
  4. Step 4: Simplify right side
    821.36x = 379,246.56
  5. Step 5: Solve for x
    x = 379,246.56/821.36
  6. Step 6: Final answer
    x = 461.73

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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.