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Finding the Fourth Proportional to 80.72, 111.32 and 66.87

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Solution

The fourth proportional to 80.72, 111.32 and 66.87 is: 92.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.72 : 111.32 = 66.87 : x
  2. Step 2: Convert to fraction form
    80.72/111.32 = 66.87/x
  3. Step 3: Cross multiply
    80.72x = 111.32 × 66.87
  4. Step 4: Simplify right side
    80.72x = 7,443.63
  5. Step 5: Solve for x
    x = 7,443.63/80.72
  6. Step 6: Final answer
    x = 92.22

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.