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Finding the Fourth Proportional to 68.79, 103.19 and 20.69

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Solution

The fourth proportional to 68.79, 103.19 and 20.69 is: 31.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.79 : 103.19 = 20.69 : x
  2. Step 2: Convert to fraction form
    68.79/103.19 = 20.69/x
  3. Step 3: Cross multiply
    68.79x = 103.19 × 20.69
  4. Step 4: Simplify right side
    68.79x = 2,135.00
  5. Step 5: Solve for x
    x = 2,135.00/68.79
  6. Step 6: Final answer
    x = 31.04

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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.