Finding the Fourth Proportional to 91,019.14, 137,020.12 and 81,864.11

Step by Step Solution

1. Step 1: Write the proportion equation
   91,019.14 : 137,020.12 = 81,864.11 : x
2. Step 2: Convert to fraction form
   91,019.14/137,020.12 = 81,864.11/x
3. Step 3: Cross multiply
   91,019.14x = 137,020.12 × 81,864.11
4. Step 4: Simplify right side
   91,019.14x = 11,217,030,313.78
5. Step 5: Solve for x
   x = 11,217,030,313.78/91,019.14
6. Step 6: Final answer
   x = 123,238.15