Finding the Fourth Proportional to 99.82, 149.61 and 54.18

Step by Step Solution

1. Step 1: Write the proportion equation
   99.82 : 149.61 = 54.18 : x
2. Step 2: Convert to fraction form
   99.82/149.61 = 54.18/x
3. Step 3: Cross multiply
   99.82x = 149.61 × 54.18
4. Step 4: Simplify right side
   99.82x = 8,105.20
5. Step 5: Solve for x
   x = 8,105.20/99.82
6. Step 6: Final answer
   x = 81.20