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Finding the Fourth Proportional to 136.72, 206.12 and 128.20

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Solution

The fourth proportional to 136.72, 206.12 and 128.20 is: 193.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.72 : 206.12 = 128.20 : x
  2. Step 2: Convert to fraction form
    136.72/206.12 = 128.20/x
  3. Step 3: Cross multiply
    136.72x = 206.12 × 128.20
  4. Step 4: Simplify right side
    136.72x = 26,424.58
  5. Step 5: Solve for x
    x = 26,424.58/136.72
  6. Step 6: Final answer
    x = 193.28

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These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.