Finding the Fourth Proportional to 78.99, 118.71 and 78.55

Step by Step Solution

1. Step 1: Write the proportion equation
   78.99 : 118.71 = 78.55 : x
2. Step 2: Convert to fraction form
   78.99/118.71 = 78.55/x
3. Step 3: Cross multiply
   78.99x = 118.71 × 78.55
4. Step 4: Simplify right side
   78.99x = 9,324.37
5. Step 5: Solve for x
   x = 9,324.37/78.99
6. Step 6: Final answer
   x = 118.04