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Finding the Fourth Proportional to 198.57, 297.80 and 138.09

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Solution

The fourth proportional to 198.57, 297.80 and 138.09 is: 207.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    198.57 : 297.80 = 138.09 : x
  2. Step 2: Convert to fraction form
    198.57/297.80 = 138.09/x
  3. Step 3: Cross multiply
    198.57x = 297.80 × 138.09
  4. Step 4: Simplify right side
    198.57x = 41,122.51
  5. Step 5: Solve for x
    x = 41,122.51/198.57
  6. Step 6: Final answer
    x = 207.09

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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.