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Finding the Fourth Proportional to 138.63, 206.77 and 136.20

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Solution

The fourth proportional to 138.63, 206.77 and 136.20 is: 203.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.63 : 206.77 = 136.20 : x
  2. Step 2: Convert to fraction form
    138.63/206.77 = 136.20/x
  3. Step 3: Cross multiply
    138.63x = 206.77 × 136.20
  4. Step 4: Simplify right side
    138.63x = 28,161.73
  5. Step 5: Solve for x
    x = 28,161.73/138.63
  6. Step 6: Final answer
    x = 203.14

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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.