Finding the Fourth Proportional to 78.96, 108.72 and 69.78

Step by Step Solution

1. Step 1: Write the proportion equation
   78.96 : 108.72 = 69.78 : x
2. Step 2: Convert to fraction form
   78.96/108.72 = 69.78/x
3. Step 3: Cross multiply
   78.96x = 108.72 × 69.78
4. Step 4: Simplify right side
   78.96x = 7,586.48
5. Step 5: Solve for x
   x = 7,586.48/78.96
6. Step 6: Final answer
   x = 96.08