Finding the Fourth Proportional to 102.86, 142.17 and 76.94

Step by Step Solution

1. Step 1: Write the proportion equation
   102.86 : 142.17 = 76.94 : x
2. Step 2: Convert to fraction form
   102.86/142.17 = 76.94/x
3. Step 3: Cross multiply
   102.86x = 142.17 × 76.94
4. Step 4: Simplify right side
   102.86x = 10,938.56
5. Step 5: Solve for x
   x = 10,938.56/102.86
6. Step 6: Final answer
   x = 106.34