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Finding the Fourth Proportional to 820.78, 1,230.91 and 272.82

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Solution

The fourth proportional to 820.78, 1,230.91 and 272.82 is: 409.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.78 : 1,230.91 = 272.82 : x
  2. Step 2: Convert to fraction form
    820.78/1,230.91 = 272.82/x
  3. Step 3: Cross multiply
    820.78x = 1,230.91 × 272.82
  4. Step 4: Simplify right side
    820.78x = 335,816.87
  5. Step 5: Solve for x
    x = 335,816.87/820.78
  6. Step 6: Final answer
    x = 409.14

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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.