Finding the Fourth Proportional to 105.88, 158.78 and 51.72

Step by Step Solution

1. Step 1: Write the proportion equation
   105.88 : 158.78 = 51.72 : x
2. Step 2: Convert to fraction form
   105.88/158.78 = 51.72/x
3. Step 3: Cross multiply
   105.88x = 158.78 × 51.72
4. Step 4: Simplify right side
   105.88x = 8,212.10
5. Step 5: Solve for x
   x = 8,212.10/105.88
6. Step 6: Final answer
   x = 77.56