Finding the Fourth Proportional to 82.50, 113.14 and 72.78

Step by Step Solution

1. Step 1: Write the proportion equation
   82.50 : 113.14 = 72.78 : x
2. Step 2: Convert to fraction form
   82.50/113.14 = 72.78/x
3. Step 3: Cross multiply
   82.50x = 113.14 × 72.78
4. Step 4: Simplify right side
   82.50x = 8,234.33
5. Step 5: Solve for x
   x = 8,234.33/82.50
6. Step 6: Final answer
   x = 99.81