Finding the Fourth Proportional to 139.71, 192.72 and 100.92

Step by Step Solution

1. Step 1: Write the proportion equation
   139.71 : 192.72 = 100.92 : x
2. Step 2: Convert to fraction form
   139.71/192.72 = 100.92/x
3. Step 3: Cross multiply
   139.71x = 192.72 × 100.92
4. Step 4: Simplify right side
   139.71x = 19,449.30
5. Step 5: Solve for x
   x = 19,449.30/139.71
6. Step 6: Final answer
   x = 139.21