Finding the Fourth Proportional to 78,360.69, 117,540.78 and 28,440.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78,360.69 : 117,540.78 = 28,440.72 : x
2. Step 2: Convert to fraction form
   78,360.69/117,540.78 = 28,440.72/x
3. Step 3: Cross multiply
   78,360.69x = 117,540.78 × 28,440.72
4. Step 4: Simplify right side
   78,360.69x = 3,342,943,976.51
5. Step 5: Solve for x
   x = 3,342,943,976.51/78,360.69
6. Step 6: Final answer
   x = 42,660.98