Finding the Fourth Proportional to 139.89, 193.29 and 107.31

Step by Step Solution

1. Step 1: Write the proportion equation
   139.89 : 193.29 = 107.31 : x
2. Step 2: Convert to fraction form
   139.89/193.29 = 107.31/x
3. Step 3: Cross multiply
   139.89x = 193.29 × 107.31
4. Step 4: Simplify right side
   139.89x = 20,741.95
5. Step 5: Solve for x
   x = 20,741.95/139.89
6. Step 6: Final answer
   x = 148.27