Finding the Fourth Proportional to 139.34, 192.16 and 109.78

Step by Step Solution

1. Step 1: Write the proportion equation
   139.34 : 192.16 = 109.78 : x
2. Step 2: Convert to fraction form
   139.34/192.16 = 109.78/x
3. Step 3: Cross multiply
   139.34x = 192.16 × 109.78
4. Step 4: Simplify right side
   139.34x = 21,095.32
5. Step 5: Solve for x
   x = 21,095.32/139.34
6. Step 6: Final answer
   x = 151.39