Finding the Fourth Proportional to 78.61, 108.52 and 54.12

Step by Step Solution

1. Step 1: Write the proportion equation
   78.61 : 108.52 = 54.12 : x
2. Step 2: Convert to fraction form
   78.61/108.52 = 54.12/x
3. Step 3: Cross multiply
   78.61x = 108.52 × 54.12
4. Step 4: Simplify right side
   78.61x = 5,873.10
5. Step 5: Solve for x
   x = 5,873.10/78.61
6. Step 6: Final answer
   x = 74.71