Finding the Fourth Proportional to 131.72, 198.56 and 123.20

Step by Step Solution

1. Step 1: Write the proportion equation
   131.72 : 198.56 = 123.20 : x
2. Step 2: Convert to fraction form
   131.72/198.56 = 123.20/x
3. Step 3: Cross multiply
   131.72x = 198.56 × 123.20
4. Step 4: Simplify right side
   131.72x = 24,462.59
5. Step 5: Solve for x
   x = 24,462.59/131.72
6. Step 6: Final answer
   x = 185.72