Finding the Fourth Proportional to 112,908.78, 155,821 and 65,165.20

Step by Step Solution

1. Step 1: Write the proportion equation
   112,908.78 : 155,821 = 65,165.20 : x
2. Step 2: Convert to fraction form
   112,908.78/155,821 = 65,165.20/x
3. Step 3: Cross multiply
   112,908.78x = 155,821 × 65,165.20
4. Step 4: Simplify right side
   112,908.78x = 10,154,105,850.10
5. Step 5: Solve for x
   x = 10,154,105,850.10/112,908.78
6. Step 6: Final answer
   x = 89,931.94