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Finding the Fourth Proportional to 819.54, 1,228.67 and 408.47

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Solution

The fourth proportional to 819.54, 1,228.67 and 408.47 is: 612.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.54 : 1,228.67 = 408.47 : x
  2. Step 2: Convert to fraction form
    819.54/1,228.67 = 408.47/x
  3. Step 3: Cross multiply
    819.54x = 1,228.67 × 408.47
  4. Step 4: Simplify right side
    819.54x = 501,871.64
  5. Step 5: Solve for x
    x = 501,871.64/819.54
  6. Step 6: Final answer
    x = 612.38

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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.