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Finding the Fourth Proportional to 213.08, 319.82 and 139.12

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Solution

The fourth proportional to 213.08, 319.82 and 139.12 is: 208.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.08 : 319.82 = 139.12 : x
  2. Step 2: Convert to fraction form
    213.08/319.82 = 139.12/x
  3. Step 3: Cross multiply
    213.08x = 319.82 × 139.12
  4. Step 4: Simplify right side
    213.08x = 44,491.86
  5. Step 5: Solve for x
    x = 44,491.86/213.08
  6. Step 6: Final answer
    x = 208.81

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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.