Finding the Fourth Proportional to 102.45, 141.37 and 86.05

Step by Step Solution

1. Step 1: Write the proportion equation
   102.45 : 141.37 = 86.05 : x
2. Step 2: Convert to fraction form
   102.45/141.37 = 86.05/x
3. Step 3: Cross multiply
   102.45x = 141.37 × 86.05
4. Step 4: Simplify right side
   102.45x = 12,164.89
5. Step 5: Solve for x
   x = 12,164.89/102.45
6. Step 6: Final answer
   x = 118.74