Finding the Fourth Proportional to 99.15, 136.71 and 88.10

Step by Step Solution

1. Step 1: Write the proportion equation
   99.15 : 136.71 = 88.10 : x
2. Step 2: Convert to fraction form
   99.15/136.71 = 88.10/x
3. Step 3: Cross multiply
   99.15x = 136.71 × 88.10
4. Step 4: Simplify right side
   99.15x = 12,043.47
5. Step 5: Solve for x
   x = 12,043.47/99.15
6. Step 6: Final answer
   x = 121.47