Finding the Fourth Proportional to 81,391.41, 122,274.72 and 78,028.45

Step by Step Solution

1. Step 1: Write the proportion equation
   81,391.41 : 122,274.72 = 78,028.45 : x
2. Step 2: Convert to fraction form
   81,391.41/122,274.72 = 78,028.45/x
3. Step 3: Cross multiply
   81,391.41x = 122,274.72 × 78,028.45
4. Step 4: Simplify right side
   81,391.41x = 9,540,906,875.78
5. Step 5: Solve for x
   x = 9,540,906,875.78/81,391.41
6. Step 6: Final answer
   x = 117,222.53