Finding the Fourth Proportional to 81,018.72, 121,527.72 and 21,860.40

Step by Step Solution

1. Step 1: Write the proportion equation
   81,018.72 : 121,527.72 = 21,860.40 : x
2. Step 2: Convert to fraction form
   81,018.72/121,527.72 = 21,860.40/x
3. Step 3: Cross multiply
   81,018.72x = 121,527.72 × 21,860.40
4. Step 4: Simplify right side
   81,018.72x = 2,656,644,570.29
5. Step 5: Solve for x
   x = 2,656,644,570.29/81,018.72
6. Step 6: Final answer
   x = 32,790.50