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Finding the Fourth Proportional to 820.38, 1,230.70 and 272.58

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Solution

The fourth proportional to 820.38, 1,230.70 and 272.58 is: 408.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.38 : 1,230.70 = 272.58 : x
  2. Step 2: Convert to fraction form
    820.38/1,230.70 = 272.58/x
  3. Step 3: Cross multiply
    820.38x = 1,230.70 × 272.58
  4. Step 4: Simplify right side
    820.38x = 335,464.21
  5. Step 5: Solve for x
    x = 335,464.21/820.38
  6. Step 6: Final answer
    x = 408.91

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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.