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Finding the Fourth Proportional to 819.47, 1,229.43 and 380.36

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Solution

The fourth proportional to 819.47, 1,229.43 and 380.36 is: 570.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.47 : 1,229.43 = 380.36 : x
  2. Step 2: Convert to fraction form
    819.47/1,229.43 = 380.36/x
  3. Step 3: Cross multiply
    819.47x = 1,229.43 × 380.36
  4. Step 4: Simplify right side
    819.47x = 467,625.99
  5. Step 5: Solve for x
    x = 467,625.99/819.47
  6. Step 6: Final answer
    x = 570.64

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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.