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Finding the Fourth Proportional to 820.88, 1,231.31 and 307.88

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Solution

The fourth proportional to 820.88, 1,231.31 and 307.88 is: 461.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.88 : 1,231.31 = 307.88 : x
  2. Step 2: Convert to fraction form
    820.88/1,231.31 = 307.88/x
  3. Step 3: Cross multiply
    820.88x = 1,231.31 × 307.88
  4. Step 4: Simplify right side
    820.88x = 379,095.72
  5. Step 5: Solve for x
    x = 379,095.72/820.88
  6. Step 6: Final answer
    x = 461.82

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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.