Finding the Fourth Proportional to 139.32, 192.58 and 106.72

Step by Step Solution

1. Step 1: Write the proportion equation
   139.32 : 192.58 = 106.72 : x
2. Step 2: Convert to fraction form
   139.32/192.58 = 106.72/x
3. Step 3: Cross multiply
   139.32x = 192.58 × 106.72
4. Step 4: Simplify right side
   139.32x = 20,551.39
5. Step 5: Solve for x
   x = 20,551.39/139.32
6. Step 6: Final answer
   x = 147.51