Finding the Fourth Proportional to 131.85, 181.98 and 100.72

Step by Step Solution

1. Step 1: Write the proportion equation
   131.85 : 181.98 = 100.72 : x
2. Step 2: Convert to fraction form
   131.85/181.98 = 100.72/x
3. Step 3: Cross multiply
   131.85x = 181.98 × 100.72
4. Step 4: Simplify right side
   131.85x = 18,329.03
5. Step 5: Solve for x
   x = 18,329.03/131.85
6. Step 6: Final answer
   x = 139.01