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Finding the Fourth Proportional to 68.72, 102.87 and 66.89

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Solution

The fourth proportional to 68.72, 102.87 and 66.89 is: 100.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    68.72 : 102.87 = 66.89 : x
  2. Step 2: Convert to fraction form
    68.72/102.87 = 66.89/x
  3. Step 3: Cross multiply
    68.72x = 102.87 × 66.89
  4. Step 4: Simplify right side
    68.72x = 6,880.97
  5. Step 5: Solve for x
    x = 6,880.97/68.72
  6. Step 6: Final answer
    x = 100.13

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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.