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Finding the Fourth Proportional to 138.31, 206.41 and 121.03

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Solution

The fourth proportional to 138.31, 206.41 and 121.03 is: 180.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.31 : 206.41 = 121.03 : x
  2. Step 2: Convert to fraction form
    138.31/206.41 = 121.03/x
  3. Step 3: Cross multiply
    138.31x = 206.41 × 121.03
  4. Step 4: Simplify right side
    138.31x = 24,981.80
  5. Step 5: Solve for x
    x = 24,981.80/138.31
  6. Step 6: Final answer
    x = 180.62

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.