Finding the Fourth Proportional to 131.33, 196.88 and 90.70

Step by Step Solution

1. Step 1: Write the proportion equation
   131.33 : 196.88 = 90.70 : x
2. Step 2: Convert to fraction form
   131.33/196.88 = 90.70/x
3. Step 3: Cross multiply
   131.33x = 196.88 × 90.70
4. Step 4: Simplify right side
   131.33x = 17,856.07
5. Step 5: Solve for x
   x = 17,856.07/131.33
6. Step 6: Final answer
   x = 135.96