Finding the Fourth Proportional to 131.28, 196.82 and 79.91

Step by Step Solution

1. Step 1: Write the proportion equation
   131.28 : 196.82 = 79.91 : x
2. Step 2: Convert to fraction form
   131.28/196.82 = 79.91/x
3. Step 3: Cross multiply
   131.28x = 196.82 × 79.91
4. Step 4: Simplify right side
   131.28x = 15,727.89
5. Step 5: Solve for x
   x = 15,727.89/131.28
6. Step 6: Final answer
   x = 119.80