Finding the Fourth Proportional to 131.63, 196.43 and 128.54

Step by Step Solution

1. Step 1: Write the proportion equation
   131.63 : 196.43 = 128.54 : x
2. Step 2: Convert to fraction form
   131.63/196.43 = 128.54/x
3. Step 3: Cross multiply
   131.63x = 196.43 × 128.54
4. Step 4: Simplify right side
   131.63x = 25,248.47
5. Step 5: Solve for x
   x = 25,248.47/131.63
6. Step 6: Final answer
   x = 191.82