Finding the Fourth Proportional to 81,015.72, 111,772.17 and 50,386.80

Step by Step Solution

1. Step 1: Write the proportion equation
   81,015.72 : 111,772.17 = 50,386.80 : x
2. Step 2: Convert to fraction form
   81,015.72/111,772.17 = 50,386.80/x
3. Step 3: Cross multiply
   81,015.72x = 111,772.17 × 50,386.80
4. Step 4: Simplify right side
   81,015.72x = 5,631,841,975.36
5. Step 5: Solve for x
   x = 5,631,841,975.36/81,015.72
6. Step 6: Final answer
   x = 69,515.42