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Finding the Fourth Proportional to 820.31, 1,230.62 and 272.39

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Solution

The fourth proportional to 820.31, 1,230.62 and 272.39 is: 408.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.31 : 1,230.62 = 272.39 : x
  2. Step 2: Convert to fraction form
    820.31/1,230.62 = 272.39/x
  3. Step 3: Cross multiply
    820.31x = 1,230.62 × 272.39
  4. Step 4: Simplify right side
    820.31x = 335,201.07
  5. Step 5: Solve for x
    x = 335,201.07/820.31
  6. Step 6: Final answer
    x = 408.63

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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.