Finding the Fourth Proportional to 99.10, 147.98 and 86.82

Step by Step Solution

1. Step 1: Write the proportion equation
   99.10 : 147.98 = 86.82 : x
2. Step 2: Convert to fraction form
   99.10/147.98 = 86.82/x
3. Step 3: Cross multiply
   99.10x = 147.98 × 86.82
4. Step 4: Simplify right side
   99.10x = 12,847.62
5. Step 5: Solve for x
   x = 12,847.62/99.10
6. Step 6: Final answer
   x = 129.64