Finding the Fourth Proportional to 81,018.72, 111,776.30 and 50,389.80

Step by Step Solution

1. Step 1: Write the proportion equation
   81,018.72 : 111,776.30 = 50,389.80 : x
2. Step 2: Convert to fraction form
   81,018.72/111,776.30 = 50,389.80/x
3. Step 3: Cross multiply
   81,018.72x = 111,776.30 × 50,389.80
4. Step 4: Simplify right side
   81,018.72x = 5,632,385,401.74
5. Step 5: Solve for x
   x = 5,632,385,401.74/81,018.72
6. Step 6: Final answer
   x = 69,519.56