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Finding the Fourth Proportional to 138.34, 206.21 and 136.72

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Solution

The fourth proportional to 138.34, 206.21 and 136.72 is: 203.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.34 : 206.21 = 136.72 : x
  2. Step 2: Convert to fraction form
    138.34/206.21 = 136.72/x
  3. Step 3: Cross multiply
    138.34x = 206.21 × 136.72
  4. Step 4: Simplify right side
    138.34x = 28,193.03
  5. Step 5: Solve for x
    x = 28,193.03/138.34
  6. Step 6: Final answer
    x = 203.80

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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.