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Finding the Fourth Proportional to 208.16, 311.78 and 142.85

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Solution

The fourth proportional to 208.16, 311.78 and 142.85 is: 213.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.16 : 311.78 = 142.85 : x
  2. Step 2: Convert to fraction form
    208.16/311.78 = 142.85/x
  3. Step 3: Cross multiply
    208.16x = 311.78 × 142.85
  4. Step 4: Simplify right side
    208.16x = 44,536.21
  5. Step 5: Solve for x
    x = 44,536.21/208.16
  6. Step 6: Final answer
    x = 213.96

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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.