Finding the Fourth Proportional to 78.88, 118.18 and 51.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.88 : 118.18 = 51.72 : x
2. Step 2: Convert to fraction form
   78.88/118.18 = 51.72/x
3. Step 3: Cross multiply
   78.88x = 118.18 × 51.72
4. Step 4: Simplify right side
   78.88x = 6,112.27
5. Step 5: Solve for x
   x = 6,112.27/78.88
6. Step 6: Final answer
   x = 77.49