Finding the Fourth Proportional to 81,116.55, 111,127.79 and 78,084.21

Step by Step Solution

1. Step 1: Write the proportion equation
   81,116.55 : 111,127.79 = 78,084.21 : x
2. Step 2: Convert to fraction form
   81,116.55/111,127.79 = 78,084.21/x
3. Step 3: Cross multiply
   81,116.55x = 111,127.79 × 78,084.21
4. Step 4: Simplify right side
   81,116.55x = 8,677,325,300.77
5. Step 5: Solve for x
   x = 8,677,325,300.77/81,116.55
6. Step 6: Final answer
   x = 106,973.55