Finding the Fourth Proportional to 139.19, 192.00 and 89.45

Step by Step Solution

1. Step 1: Write the proportion equation
   139.19 : 192.00 = 89.45 : x
2. Step 2: Convert to fraction form
   139.19/192.00 = 89.45/x
3. Step 3: Cross multiply
   139.19x = 192.00 × 89.45
4. Step 4: Simplify right side
   139.19x = 17,174.82
5. Step 5: Solve for x
   x = 17,174.82/139.19
6. Step 6: Final answer
   x = 123.39