Finding the Fourth Proportional to 71,640.72, 107,439.48 and 30,078.48

Step by Step Solution

1. Step 1: Write the proportion equation
   71,640.72 : 107,439.48 = 30,078.48 : x
2. Step 2: Convert to fraction form
   71,640.72/107,439.48 = 30,078.48/x
3. Step 3: Cross multiply
   71,640.72x = 107,439.48 × 30,078.48
4. Step 4: Simplify right side
   71,640.72x = 3,231,616,250.39
5. Step 5: Solve for x
   x = 3,231,616,250.39/71,640.72
6. Step 6: Final answer
   x = 45,108.65