Finding the Fourth Proportional to 131.89, 197.69 and 86.27

Step by Step Solution

1. Step 1: Write the proportion equation
   131.89 : 197.69 = 86.27 : x
2. Step 2: Convert to fraction form
   131.89/197.69 = 86.27/x
3. Step 3: Cross multiply
   131.89x = 197.69 × 86.27
4. Step 4: Simplify right side
   131.89x = 17,054.72
5. Step 5: Solve for x
   x = 17,054.72/131.89
6. Step 6: Final answer
   x = 129.31