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Finding the Fourth Proportional to 819.16, 1,228.74 and 408.49

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Solution

The fourth proportional to 819.16, 1,228.74 and 408.49 is: 612.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.16 : 1,228.74 = 408.49 : x
  2. Step 2: Convert to fraction form
    819.16/1,228.74 = 408.49/x
  3. Step 3: Cross multiply
    819.16x = 1,228.74 × 408.49
  4. Step 4: Simplify right side
    819.16x = 501,928.00
  5. Step 5: Solve for x
    x = 501,928.00/819.16
  6. Step 6: Final answer
    x = 612.74

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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.