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Finding the Fourth Proportional to 68.72, 103.09 and 20.63

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Solution

The fourth proportional to 68.72, 103.09 and 20.63 is: 30.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.72 : 103.09 = 20.63 : x
  2. Step 2: Convert to fraction form
    68.72/103.09 = 20.63/x
  3. Step 3: Cross multiply
    68.72x = 103.09 × 20.63
  4. Step 4: Simplify right side
    68.72x = 2,126.75
  5. Step 5: Solve for x
    x = 2,126.75/68.72
  6. Step 6: Final answer
    x = 30.95

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.