Finding the Fourth Proportional to 139.24, 192.15 and 89.38

Step by Step Solution

1. Step 1: Write the proportion equation
   139.24 : 192.15 = 89.38 : x
2. Step 2: Convert to fraction form
   139.24/192.15 = 89.38/x
3. Step 3: Cross multiply
   139.24x = 192.15 × 89.38
4. Step 4: Simplify right side
   139.24x = 17,174.37
5. Step 5: Solve for x
   x = 17,174.37/139.24
6. Step 6: Final answer
   x = 123.34