Finding the Fourth Proportional to 143.10, 196.31 and 139.52

Step by Step Solution

1. Step 1: Write the proportion equation
   143.10 : 196.31 = 139.52 : x
2. Step 2: Convert to fraction form
   143.10/196.31 = 139.52/x
3. Step 3: Cross multiply
   143.10x = 196.31 × 139.52
4. Step 4: Simplify right side
   143.10x = 27,389.17
5. Step 5: Solve for x
   x = 27,389.17/143.10
6. Step 6: Final answer
   x = 191.40