Finding the Fourth Proportional to 78.60, 108.42 and 54.06

Step by Step Solution

1. Step 1: Write the proportion equation
   78.60 : 108.42 = 54.06 : x
2. Step 2: Convert to fraction form
   78.60/108.42 = 54.06/x
3. Step 3: Cross multiply
   78.60x = 108.42 × 54.06
4. Step 4: Simplify right side
   78.60x = 5,860.78
5. Step 5: Solve for x
   x = 5,860.78/78.60
6. Step 6: Final answer
   x = 74.56