Finding the Fourth Proportional to 104.18, 156.33 and 78.56

Step by Step Solution

1. Step 1: Write the proportion equation
   104.18 : 156.33 = 78.56 : x
2. Step 2: Convert to fraction form
   104.18/156.33 = 78.56/x
3. Step 3: Cross multiply
   104.18x = 156.33 × 78.56
4. Step 4: Simplify right side
   104.18x = 12,280.50
5. Step 5: Solve for x
   x = 12,280.50/104.18
6. Step 6: Final answer
   x = 117.88