Finding the Fourth Proportional to 139.73, 192.69 and 90.63

Step by Step Solution

1. Step 1: Write the proportion equation
   139.73 : 192.69 = 90.63 : x
2. Step 2: Convert to fraction form
   139.73/192.69 = 90.63/x
3. Step 3: Cross multiply
   139.73x = 192.69 × 90.63
4. Step 4: Simplify right side
   139.73x = 17,463.49
5. Step 5: Solve for x
   x = 17,463.49/139.73
6. Step 6: Final answer
   x = 124.98