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Finding the Fourth Proportional to 208.05, 311.67 and 105.21

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Solution

The fourth proportional to 208.05, 311.67 and 105.21 is: 157.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.05 : 311.67 = 105.21 : x
  2. Step 2: Convert to fraction form
    208.05/311.67 = 105.21/x
  3. Step 3: Cross multiply
    208.05x = 311.67 × 105.21
  4. Step 4: Simplify right side
    208.05x = 32,790.80
  5. Step 5: Solve for x
    x = 32,790.80/208.05
  6. Step 6: Final answer
    x = 157.61

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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.