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Finding the Fourth Proportional to 385.54, 578.26 and 138.74

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Solution

The fourth proportional to 385.54, 578.26 and 138.74 is: 208.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.54 : 578.26 = 138.74 : x
  2. Step 2: Convert to fraction form
    385.54/578.26 = 138.74/x
  3. Step 3: Cross multiply
    385.54x = 578.26 × 138.74
  4. Step 4: Simplify right side
    385.54x = 80,227.79
  5. Step 5: Solve for x
    x = 80,227.79/385.54
  6. Step 6: Final answer
    x = 208.09

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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.