Finding the Fourth Proportional to 82.55, 123.60 and 72.81

Step by Step Solution

1. Step 1: Write the proportion equation
   82.55 : 123.60 = 72.81 : x
2. Step 2: Convert to fraction form
   82.55/123.60 = 72.81/x
3. Step 3: Cross multiply
   82.55x = 123.60 × 72.81
4. Step 4: Simplify right side
   82.55x = 8,999.78
5. Step 5: Solve for x
   x = 8,999.78/82.55
6. Step 6: Final answer
   x = 109.03