Finding the Fourth Proportional to 82.47, 113.58 and 78.42

Step by Step Solution

1. Step 1: Write the proportion equation
   82.47 : 113.58 = 78.42 : x
2. Step 2: Convert to fraction form
   82.47/113.58 = 78.42/x
3. Step 3: Cross multiply
   82.47x = 113.58 × 78.42
4. Step 4: Simplify right side
   82.47x = 8,906.94
5. Step 5: Solve for x
   x = 8,906.94/82.47
6. Step 6: Final answer
   x = 108.00