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Finding the Fourth Proportional to 828.87, 1,243.31 and 280.75

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Solution

The fourth proportional to 828.87, 1,243.31 and 280.75 is: 421.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.87 : 1,243.31 = 280.75 : x
  2. Step 2: Convert to fraction form
    828.87/1,243.31 = 280.75/x
  3. Step 3: Cross multiply
    828.87x = 1,243.31 × 280.75
  4. Step 4: Simplify right side
    828.87x = 349,059.28
  5. Step 5: Solve for x
    x = 349,059.28/828.87
  6. Step 6: Final answer
    x = 421.13

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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.