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Finding the Fourth Proportional to 820.76, 1,230.85 and 272.80

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Solution

The fourth proportional to 820.76, 1,230.85 and 272.80 is: 409.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.76 : 1,230.85 = 272.80 : x
  2. Step 2: Convert to fraction form
    820.76/1,230.85 = 272.80/x
  3. Step 3: Cross multiply
    820.76x = 1,230.85 × 272.80
  4. Step 4: Simplify right side
    820.76x = 335,768.36
  5. Step 5: Solve for x
    x = 335,768.36/820.76
  6. Step 6: Final answer
    x = 409.09

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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.