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Finding the Fourth Proportional to 385.91, 578.99 and 139.19

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Solution

The fourth proportional to 385.91, 578.99 and 139.19 is: 208.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.91 : 578.99 = 139.19 : x
  2. Step 2: Convert to fraction form
    385.91/578.99 = 139.19/x
  3. Step 3: Cross multiply
    385.91x = 578.99 × 139.19
  4. Step 4: Simplify right side
    385.91x = 80,590.98
  5. Step 5: Solve for x
    x = 80,590.98/385.91
  6. Step 6: Final answer
    x = 208.83

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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.