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Finding the Fourth Proportional to 80.88, 121.17 and 66.42

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Solution

The fourth proportional to 80.88, 121.17 and 66.42 is: 99.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.88 : 121.17 = 66.42 : x
  2. Step 2: Convert to fraction form
    80.88/121.17 = 66.42/x
  3. Step 3: Cross multiply
    80.88x = 121.17 × 66.42
  4. Step 4: Simplify right side
    80.88x = 8,048.36
  5. Step 5: Solve for x
    x = 8,048.36/80.88
  6. Step 6: Final answer
    x = 99.51

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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.