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Finding the Fourth Proportional to 231.31, 319.09 and 138.08

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Solution

The fourth proportional to 231.31, 319.09 and 138.08 is: 190.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    231.31 : 319.09 = 138.08 : x
  2. Step 2: Convert to fraction form
    231.31/319.09 = 138.08/x
  3. Step 3: Cross multiply
    231.31x = 319.09 × 138.08
  4. Step 4: Simplify right side
    231.31x = 44,059.76
  5. Step 5: Solve for x
    x = 44,059.76/231.31
  6. Step 6: Final answer
    x = 190.48

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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.