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Finding the Fourth Proportional to 819.59, 1,228.77 and 387.05

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Solution

The fourth proportional to 819.59, 1,228.77 and 387.05 is: 580.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.59 : 1,228.77 = 387.05 : x
  2. Step 2: Convert to fraction form
    819.59/1,228.77 = 387.05/x
  3. Step 3: Cross multiply
    819.59x = 1,228.77 × 387.05
  4. Step 4: Simplify right side
    819.59x = 475,589.28
  5. Step 5: Solve for x
    x = 475,589.28/819.59
  6. Step 6: Final answer
    x = 580.28

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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.