Finding the Fourth Proportional to 88.04, 121.38 and 86.15

Step by Step Solution

1. Step 1: Write the proportion equation
   88.04 : 121.38 = 86.15 : x
2. Step 2: Convert to fraction form
   88.04/121.38 = 86.15/x
3. Step 3: Cross multiply
   88.04x = 121.38 × 86.15
4. Step 4: Simplify right side
   88.04x = 10,456.89
5. Step 5: Solve for x
   x = 10,456.89/88.04
6. Step 6: Final answer
   x = 118.77