Finding the Fourth Proportional to 139.37, 192.29 and 86.83

Step by Step Solution

1. Step 1: Write the proportion equation
   139.37 : 192.29 = 86.83 : x
2. Step 2: Convert to fraction form
   139.37/192.29 = 86.83/x
3. Step 3: Cross multiply
   139.37x = 192.29 × 86.83
4. Step 4: Simplify right side
   139.37x = 16,696.76
5. Step 5: Solve for x
   x = 16,696.76/139.37
6. Step 6: Final answer
   x = 119.80