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Finding the Fourth Proportional to 551.78, 827.82 and 389.78

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Solution

The fourth proportional to 551.78, 827.82 and 389.78 is: 584.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    551.78 : 827.82 = 389.78 : x
  2. Step 2: Convert to fraction form
    551.78/827.82 = 389.78/x
  3. Step 3: Cross multiply
    551.78x = 827.82 × 389.78
  4. Step 4: Simplify right side
    551.78x = 322,667.68
  5. Step 5: Solve for x
    x = 322,667.68/551.78
  6. Step 6: Final answer
    x = 584.78

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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.