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Finding the Fourth Proportional to 198.75, 299.19 and 138.31

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Solution

The fourth proportional to 198.75, 299.19 and 138.31 is: 208.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.75 : 299.19 = 138.31 : x
  2. Step 2: Convert to fraction form
    198.75/299.19 = 138.31/x
  3. Step 3: Cross multiply
    198.75x = 299.19 × 138.31
  4. Step 4: Simplify right side
    198.75x = 41,380.74
  5. Step 5: Solve for x
    x = 41,380.74/198.75
  6. Step 6: Final answer
    x = 208.20

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.