Finding the Fourth Proportional to 78.80, 118.24 and 30.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.80 : 118.24 = 30.72 : x
2. Step 2: Convert to fraction form
   78.80/118.24 = 30.72/x
3. Step 3: Cross multiply
   78.80x = 118.24 × 30.72
4. Step 4: Simplify right side
   78.80x = 3,632.33
5. Step 5: Solve for x
   x = 3,632.33/78.80
6. Step 6: Final answer
   x = 46.10