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Finding the Fourth Proportional to 138.28, 191.10 and 103.42

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Solution

The fourth proportional to 138.28, 191.10 and 103.42 is: 142.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.28 : 191.10 = 103.42 : x
  2. Step 2: Convert to fraction form
    138.28/191.10 = 103.42/x
  3. Step 3: Cross multiply
    138.28x = 191.10 × 103.42
  4. Step 4: Simplify right side
    138.28x = 19,763.56
  5. Step 5: Solve for x
    x = 19,763.56/138.28
  6. Step 6: Final answer
    x = 142.92

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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.