Finding the Fourth Proportional to 113.37, 156.42 and 78.42

Step by Step Solution

1. Step 1: Write the proportion equation
   113.37 : 156.42 = 78.42 : x
2. Step 2: Convert to fraction form
   113.37/156.42 = 78.42/x
3. Step 3: Cross multiply
   113.37x = 156.42 × 78.42
4. Step 4: Simplify right side
   113.37x = 12,266.46
5. Step 5: Solve for x
   x = 12,266.46/113.37
6. Step 6: Final answer
   x = 108.20