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Finding the Fourth Proportional to 819.19, 1,228.32 and 380.88

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Solution

The fourth proportional to 819.19, 1,228.32 and 380.88 is: 571.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.19 : 1,228.32 = 380.88 : x
  2. Step 2: Convert to fraction form
    819.19/1,228.32 = 380.88/x
  3. Step 3: Cross multiply
    819.19x = 1,228.32 × 380.88
  4. Step 4: Simplify right side
    819.19x = 467,834.48
  5. Step 5: Solve for x
    x = 467,834.48/819.19
  6. Step 6: Final answer
    x = 571.10

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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.