Finding the Fourth Proportional to 131.41, 196.57 and 90.71

Step by Step Solution

1. Step 1: Write the proportion equation
   131.41 : 196.57 = 90.71 : x
2. Step 2: Convert to fraction form
   131.41/196.57 = 90.71/x
3. Step 3: Cross multiply
   131.41x = 196.57 × 90.71
4. Step 4: Simplify right side
   131.41x = 17,830.86
5. Step 5: Solve for x
   x = 17,830.86/131.41
6. Step 6: Final answer
   x = 135.69