Finding the Fourth Proportional to 78.78, 118.59 and 69.96

Step by Step Solution

1. Step 1: Write the proportion equation
   78.78 : 118.59 = 69.96 : x
2. Step 2: Convert to fraction form
   78.78/118.59 = 69.96/x
3. Step 3: Cross multiply
   78.78x = 118.59 × 69.96
4. Step 4: Simplify right side
   78.78x = 8,296.56
5. Step 5: Solve for x
   x = 8,296.56/78.78
6. Step 6: Final answer
   x = 105.31