Finding the Fourth Proportional to 106.78, 147.42 and 82.17

Step by Step Solution

1. Step 1: Write the proportion equation
   106.78 : 147.42 = 82.17 : x
2. Step 2: Convert to fraction form
   106.78/147.42 = 82.17/x
3. Step 3: Cross multiply
   106.78x = 147.42 × 82.17
4. Step 4: Simplify right side
   106.78x = 12,113.50
5. Step 5: Solve for x
   x = 12,113.50/106.78
6. Step 6: Final answer
   x = 113.45