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Finding the Fourth Proportional to 80.70, 121.67 and 77.22

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Solution

The fourth proportional to 80.70, 121.67 and 77.22 is: 116.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.70 : 121.67 = 77.22 : x
  2. Step 2: Convert to fraction form
    80.70/121.67 = 77.22/x
  3. Step 3: Cross multiply
    80.70x = 121.67 × 77.22
  4. Step 4: Simplify right side
    80.70x = 9,394.97
  5. Step 5: Solve for x
    x = 9,394.97/80.70
  6. Step 6: Final answer
    x = 116.42

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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.