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Finding the Fourth Proportional to 828.78, 1,243.30 and 280.82

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Solution

The fourth proportional to 828.78, 1,243.30 and 280.82 is: 421.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.78 : 1,243.30 = 280.82 : x
  2. Step 2: Convert to fraction form
    828.78/1,243.30 = 280.82/x
  3. Step 3: Cross multiply
    828.78x = 1,243.30 × 280.82
  4. Step 4: Simplify right side
    828.78x = 349,136.59
  5. Step 5: Solve for x
    x = 349,136.59/828.78
  6. Step 6: Final answer
    x = 421.27

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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.