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Finding the Fourth Proportional to 819.24, 1,228.05 and 385.89

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Solution

The fourth proportional to 819.24, 1,228.05 and 385.89 is: 578.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    819.24 : 1,228.05 = 385.89 : x
  2. Step 2: Convert to fraction form
    819.24/1,228.05 = 385.89/x
  3. Step 3: Cross multiply
    819.24x = 1,228.05 × 385.89
  4. Step 4: Simplify right side
    819.24x = 473,892.21
  5. Step 5: Solve for x
    x = 473,892.21/819.24
  6. Step 6: Final answer
    x = 578.45

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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.