Finding the Fourth Proportional to 81,128.49, 111,956.78 and 45,318.18

Step by Step Solution

1. Step 1: Write the proportion equation
   81,128.49 : 111,956.78 = 45,318.18 : x
2. Step 2: Convert to fraction form
   81,128.49/111,956.78 = 45,318.18/x
3. Step 3: Cross multiply
   81,128.49x = 111,956.78 × 45,318.18
4. Step 4: Simplify right side
   81,128.49x = 5,073,678,041.39
5. Step 5: Solve for x
   x = 5,073,678,041.39/81,128.49
6. Step 6: Final answer
   x = 62,538.80