Finding the Fourth Proportional to 100.18, 150.18 and 86.41

Step by Step Solution

1. Step 1: Write the proportion equation
   100.18 : 150.18 = 86.41 : x
2. Step 2: Convert to fraction form
   100.18/150.18 = 86.41/x
3. Step 3: Cross multiply
   100.18x = 150.18 × 86.41
4. Step 4: Simplify right side
   100.18x = 12,977.05
5. Step 5: Solve for x
   x = 12,977.05/100.18
6. Step 6: Final answer
   x = 129.54