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Finding the Fourth Proportional to 208.39, 312.89 and 131.68

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Solution

The fourth proportional to 208.39, 312.89 and 131.68 is: 197.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.39 : 312.89 = 131.68 : x
  2. Step 2: Convert to fraction form
    208.39/312.89 = 131.68/x
  3. Step 3: Cross multiply
    208.39x = 312.89 × 131.68
  4. Step 4: Simplify right side
    208.39x = 41,201.36
  5. Step 5: Solve for x
    x = 41,201.36/208.39
  6. Step 6: Final answer
    x = 197.71

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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.