Finding the Fourth Proportional to 142.31, 196.15 and 105.63

Step by Step Solution

1. Step 1: Write the proportion equation
   142.31 : 196.15 = 105.63 : x
2. Step 2: Convert to fraction form
   142.31/196.15 = 105.63/x
3. Step 3: Cross multiply
   142.31x = 196.15 × 105.63
4. Step 4: Simplify right side
   142.31x = 20,718.78
5. Step 5: Solve for x
   x = 20,718.78/142.31
6. Step 6: Final answer
   x = 145.59