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Finding the Fourth Proportional to 197.12, 271.78 and 138.80

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Solution

The fourth proportional to 197.12, 271.78 and 138.80 is: 191.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    197.12 : 271.78 = 138.80 : x
  2. Step 2: Convert to fraction form
    197.12/271.78 = 138.80/x
  3. Step 3: Cross multiply
    197.12x = 271.78 × 138.80
  4. Step 4: Simplify right side
    197.12x = 37,721.36
  5. Step 5: Solve for x
    x = 37,721.36/197.12
  6. Step 6: Final answer
    x = 191.37

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.