Finding the Fourth Proportional to 82.17, 123.15 and 72.51

Step by Step Solution

1. Step 1: Write the proportion equation
   82.17 : 123.15 = 72.51 : x
2. Step 2: Convert to fraction form
   82.17/123.15 = 72.51/x
3. Step 3: Cross multiply
   82.17x = 123.15 × 72.51
4. Step 4: Simplify right side
   82.17x = 8,929.61
5. Step 5: Solve for x
   x = 8,929.61/82.17
6. Step 6: Final answer
   x = 108.67