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Finding the Fourth Proportional to 820.57, 1,230.89 and 272.81

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Solution

The fourth proportional to 820.57, 1,230.89 and 272.81 is: 409.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.57 : 1,230.89 = 272.81 : x
  2. Step 2: Convert to fraction form
    820.57/1,230.89 = 272.81/x
  3. Step 3: Cross multiply
    820.57x = 1,230.89 × 272.81
  4. Step 4: Simplify right side
    820.57x = 335,791.58
  5. Step 5: Solve for x
    x = 335,791.58/820.57
  6. Step 6: Final answer
    x = 409.22

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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.