Finding the Fourth Proportional to 139.98, 192.81 and 100.59

Step by Step Solution

1. Step 1: Write the proportion equation
   139.98 : 192.81 = 100.59 : x
2. Step 2: Convert to fraction form
   139.98/192.81 = 100.59/x
3. Step 3: Cross multiply
   139.98x = 192.81 × 100.59
4. Step 4: Simplify right side
   139.98x = 19,394.76
5. Step 5: Solve for x
   x = 19,394.76/139.98
6. Step 6: Final answer
   x = 138.55