Finding the Fourth Proportional to 100.89, 139.28 and 82.51

Step by Step Solution

1. Step 1: Write the proportion equation
   100.89 : 139.28 = 82.51 : x
2. Step 2: Convert to fraction form
   100.89/139.28 = 82.51/x
3. Step 3: Cross multiply
   100.89x = 139.28 × 82.51
4. Step 4: Simplify right side
   100.89x = 11,492.20
5. Step 5: Solve for x
   x = 11,492.20/100.89
6. Step 6: Final answer
   x = 113.91