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Finding the Fourth Proportional to 819.74, 1,229.02 and 386.66

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Solution

The fourth proportional to 819.74, 1,229.02 and 386.66 is: 579.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.74 : 1,229.02 = 386.66 : x
  2. Step 2: Convert to fraction form
    819.74/1,229.02 = 386.66/x
  3. Step 3: Cross multiply
    819.74x = 1,229.02 × 386.66
  4. Step 4: Simplify right side
    819.74x = 475,212.87
  5. Step 5: Solve for x
    x = 475,212.87/819.74
  6. Step 6: Final answer
    x = 579.71

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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.