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Finding the Fourth Proportional to 385.35, 578.04 and 138.54

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Solution

The fourth proportional to 385.35, 578.04 and 138.54 is: 207.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.35 : 578.04 = 138.54 : x
  2. Step 2: Convert to fraction form
    385.35/578.04 = 138.54/x
  3. Step 3: Cross multiply
    385.35x = 578.04 × 138.54
  4. Step 4: Simplify right side
    385.35x = 80,081.66
  5. Step 5: Solve for x
    x = 80,081.66/385.35
  6. Step 6: Final answer
    x = 207.82

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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.