Finding the Fourth Proportional to 131.56, 181.56 and 72.55

Step by Step Solution

1. Step 1: Write the proportion equation
   131.56 : 181.56 = 72.55 : x
2. Step 2: Convert to fraction form
   131.56/181.56 = 72.55/x
3. Step 3: Cross multiply
   131.56x = 181.56 × 72.55
4. Step 4: Simplify right side
   131.56x = 13,172.18
5. Step 5: Solve for x
   x = 13,172.18/131.56
6. Step 6: Final answer
   x = 100.12