Finding the Fourth Proportional to 131.37, 196.83 and 90.72

Step by Step Solution

1. Step 1: Write the proportion equation
   131.37 : 196.83 = 90.72 : x
2. Step 2: Convert to fraction form
   131.37/196.83 = 90.72/x
3. Step 3: Cross multiply
   131.37x = 196.83 × 90.72
4. Step 4: Simplify right side
   131.37x = 17,856.42
5. Step 5: Solve for x
   x = 17,856.42/131.37
6. Step 6: Final answer
   x = 135.92