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Finding the Fourth Proportional to 820.39, 1,230.80 and 272.73

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Solution

The fourth proportional to 820.39, 1,230.80 and 272.73 is: 409.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.39 : 1,230.80 = 272.73 : x
  2. Step 2: Convert to fraction form
    820.39/1,230.80 = 272.73/x
  3. Step 3: Cross multiply
    820.39x = 1,230.80 × 272.73
  4. Step 4: Simplify right side
    820.39x = 335,676.08
  5. Step 5: Solve for x
    x = 335,676.08/820.39
  6. Step 6: Final answer
    x = 409.17

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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.