Finding the Fourth Proportional to 105.31, 156.78 and 104.80

Step by Step Solution

1. Step 1: Write the proportion equation
   105.31 : 156.78 = 104.80 : x
2. Step 2: Convert to fraction form
   105.31/156.78 = 104.80/x
3. Step 3: Cross multiply
   105.31x = 156.78 × 104.80
4. Step 4: Simplify right side
   105.31x = 16,429.24
5. Step 5: Solve for x
   x = 16,429.24/105.31
6. Step 6: Final answer
   x = 156.02