Finding the Fourth Proportional to 131.83, 181.91 and 72.81

Step by Step Solution

1. Step 1: Write the proportion equation
   131.83 : 181.91 = 72.81 : x
2. Step 2: Convert to fraction form
   131.83/181.91 = 72.81/x
3. Step 3: Cross multiply
   131.83x = 181.91 × 72.81
4. Step 4: Simplify right side
   131.83x = 13,245.05
5. Step 5: Solve for x
   x = 13,245.05/131.83
6. Step 6: Final answer
   x = 100.47