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Finding the Fourth Proportional to 231.38, 319.21 and 138.11

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Solution

The fourth proportional to 231.38, 319.21 and 138.11 is: 190.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.38 : 319.21 = 138.11 : x
  2. Step 2: Convert to fraction form
    231.38/319.21 = 138.11/x
  3. Step 3: Cross multiply
    231.38x = 319.21 × 138.11
  4. Step 4: Simplify right side
    231.38x = 44,084.15
  5. Step 5: Solve for x
    x = 44,084.15/231.38
  6. Step 6: Final answer
    x = 190.53

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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.