Finding the Fourth Proportional to 131.79, 196.89 and 115.59

Step by Step Solution

1. Step 1: Write the proportion equation
   131.79 : 196.89 = 115.59 : x
2. Step 2: Convert to fraction form
   131.79/196.89 = 115.59/x
3. Step 3: Cross multiply
   131.79x = 196.89 × 115.59
4. Step 4: Simplify right side
   131.79x = 22,758.52
5. Step 5: Solve for x
   x = 22,758.52/131.79
6. Step 6: Final answer
   x = 172.69