Finding the Fourth Proportional to 109,111.20, 163,513.20 and 80,810.40

Step by Step Solution

1. Step 1: Write the proportion equation
   109,111.20 : 163,513.20 = 80,810.40 : x
2. Step 2: Convert to fraction form
   109,111.20/163,513.20 = 80,810.40/x
3. Step 3: Cross multiply
   109,111.20x = 163,513.20 × 80,810.40
4. Step 4: Simplify right side
   109,111.20x = 13,213,567,097.28
5. Step 5: Solve for x
   x = 13,213,567,097.28/109,111.20
6. Step 6: Final answer
   x = 121,101.84