Finding the Fourth Proportional to 78.78, 108.69 and 51.14

Step by Step Solution

1. Step 1: Write the proportion equation
   78.78 : 108.69 = 51.14 : x
2. Step 2: Convert to fraction form
   78.78/108.69 = 51.14/x
3. Step 3: Cross multiply
   78.78x = 108.69 × 51.14
4. Step 4: Simplify right side
   78.78x = 5,558.41
5. Step 5: Solve for x
   x = 5,558.41/78.78
6. Step 6: Final answer
   x = 70.56