Finding the Fourth Proportional to 81,019.20, 111,803.58 and 50,820.78

Step by Step Solution

1. Step 1: Write the proportion equation
   81,019.20 : 111,803.58 = 50,820.78 : x
2. Step 2: Convert to fraction form
   81,019.20/111,803.58 = 50,820.78/x
3. Step 3: Cross multiply
   81,019.20x = 111,803.58 × 50,820.78
4. Step 4: Simplify right side
   81,019.20x = 5,681,945,142.39
5. Step 5: Solve for x
   x = 5,681,945,142.39/81,019.20
6. Step 6: Final answer
   x = 70,130.85