Finding the Fourth Proportional to 142.58, 196.76 and 83.57

Step by Step Solution

1. Step 1: Write the proportion equation
   142.58 : 196.76 = 83.57 : x
2. Step 2: Convert to fraction form
   142.58/196.76 = 83.57/x
3. Step 3: Cross multiply
   142.58x = 196.76 × 83.57
4. Step 4: Simplify right side
   142.58x = 16,443.23
5. Step 5: Solve for x
   x = 16,443.23/142.58
6. Step 6: Final answer
   x = 115.33