Finding the Fourth Proportional to 100.81, 139.31 and 82.38

Step by Step Solution

1. Step 1: Write the proportion equation
   100.81 : 139.31 = 82.38 : x
2. Step 2: Convert to fraction form
   100.81/139.31 = 82.38/x
3. Step 3: Cross multiply
   100.81x = 139.31 × 82.38
4. Step 4: Simplify right side
   100.81x = 11,476.78
5. Step 5: Solve for x
   x = 11,476.78/100.81
6. Step 6: Final answer
   x = 113.84