Finding the Fourth Proportional to 99.82, 149.91 and 81.82

Step by Step Solution

1. Step 1: Write the proportion equation
   99.82 : 149.91 = 81.82 : x
2. Step 2: Convert to fraction form
   99.82/149.91 = 81.82/x
3. Step 3: Cross multiply
   99.82x = 149.91 × 81.82
4. Step 4: Simplify right side
   99.82x = 12,265.64
5. Step 5: Solve for x
   x = 12,265.64/99.82
6. Step 6: Final answer
   x = 122.88