Finding the Fourth Proportional to 78.48, 117.72 and 48.12

Step by Step Solution

1. Step 1: Write the proportion equation
   78.48 : 117.72 = 48.12 : x
2. Step 2: Convert to fraction form
   78.48/117.72 = 48.12/x
3. Step 3: Cross multiply
   78.48x = 117.72 × 48.12
4. Step 4: Simplify right side
   78.48x = 5,664.69
5. Step 5: Solve for x
   x = 5,664.69/78.48
6. Step 6: Final answer
   x = 72.18