Finding the Fourth Proportional to 78.24, 107.91 and 48.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.24 : 107.91 = 48.72 : x
2. Step 2: Convert to fraction form
   78.24/107.91 = 48.72/x
3. Step 3: Cross multiply
   78.24x = 107.91 × 48.72
4. Step 4: Simplify right side
   78.24x = 5,257.38
5. Step 5: Solve for x
   x = 5,257.38/78.24
6. Step 6: Final answer
   x = 67.20