Finding the Fourth Proportional to 142.79, 196.96 and 99.05

Step by Step Solution

1. Step 1: Write the proportion equation
   142.79 : 196.96 = 99.05 : x
2. Step 2: Convert to fraction form
   142.79/196.96 = 99.05/x
3. Step 3: Cross multiply
   142.79x = 196.96 × 99.05
4. Step 4: Simplify right side
   142.79x = 19,508.89
5. Step 5: Solve for x
   x = 19,508.89/142.79
6. Step 6: Final answer
   x = 136.63