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Finding the Fourth Proportional to 68.57, 102.74 and 54.20

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Solution

The fourth proportional to 68.57, 102.74 and 54.20 is: 81.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.57 : 102.74 = 54.20 : x
  2. Step 2: Convert to fraction form
    68.57/102.74 = 54.20/x
  3. Step 3: Cross multiply
    68.57x = 102.74 × 54.20
  4. Step 4: Simplify right side
    68.57x = 5,567.72
  5. Step 5: Solve for x
    x = 5,567.72/68.57
  6. Step 6: Final answer
    x = 81.20

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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.