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Finding the Fourth Proportional to 80.82, 121.77 and 66.69

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Solution

The fourth proportional to 80.82, 121.77 and 66.69 is: 100.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.82 : 121.77 = 66.69 : x
  2. Step 2: Convert to fraction form
    80.82/121.77 = 66.69/x
  3. Step 3: Cross multiply
    80.82x = 121.77 × 66.69
  4. Step 4: Simplify right side
    80.82x = 8,120.23
  5. Step 5: Solve for x
    x = 8,120.23/80.82
  6. Step 6: Final answer
    x = 100.48

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.