Finding the Fourth Proportional to 86.16, 118.81 and 72.50

Step by Step Solution

1. Step 1: Write the proportion equation
   86.16 : 118.81 = 72.50 : x
2. Step 2: Convert to fraction form
   86.16/118.81 = 72.50/x
3. Step 3: Cross multiply
   86.16x = 118.81 × 72.50
4. Step 4: Simplify right side
   86.16x = 8,612.95
5. Step 5: Solve for x
   x = 8,612.95/86.16
6. Step 6: Final answer
   x = 99.96