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Finding the Fourth Proportional to 819.56, 1,228.08 and 385.76

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Solution

The fourth proportional to 819.56, 1,228.08 and 385.76 is: 578.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.56 : 1,228.08 = 385.76 : x
  2. Step 2: Convert to fraction form
    819.56/1,228.08 = 385.76/x
  3. Step 3: Cross multiply
    819.56x = 1,228.08 × 385.76
  4. Step 4: Simplify right side
    819.56x = 473,744.14
  5. Step 5: Solve for x
    x = 473,744.14/819.56
  6. Step 6: Final answer
    x = 578.05

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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.