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Finding the Fourth Proportional to 208.92, 313.18 and 71.90

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Solution

The fourth proportional to 208.92, 313.18 and 71.90 is: 107.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.92 : 313.18 = 71.90 : x
  2. Step 2: Convert to fraction form
    208.92/313.18 = 71.90/x
  3. Step 3: Cross multiply
    208.92x = 313.18 × 71.90
  4. Step 4: Simplify right side
    208.92x = 22,517.64
  5. Step 5: Solve for x
    x = 22,517.64/208.92
  6. Step 6: Final answer
    x = 107.78

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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.