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Finding the Fourth Proportional to 820.79, 1,231 and 272.83

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Solution

The fourth proportional to 820.79, 1,231 and 272.83 is: 409.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.79 : 1,231 = 272.83 : x
  2. Step 2: Convert to fraction form
    820.79/1,231 = 272.83/x
  3. Step 3: Cross multiply
    820.79x = 1,231 × 272.83
  4. Step 4: Simplify right side
    820.79x = 335,853.73
  5. Step 5: Solve for x
    x = 335,853.73/820.79
  6. Step 6: Final answer
    x = 409.18

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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.