Finding the Fourth Proportional to 78.69, 108.42 and 54.08

Step by Step Solution

1. Step 1: Write the proportion equation
   78.69 : 108.42 = 54.08 : x
2. Step 2: Convert to fraction form
   78.69/108.42 = 54.08/x
3. Step 3: Cross multiply
   78.69x = 108.42 × 54.08
4. Step 4: Simplify right side
   78.69x = 5,863.62
5. Step 5: Solve for x
   x = 5,863.62/78.69
6. Step 6: Final answer
   x = 74.52