Finding the Fourth Proportional to 20,402.31, 30,578.86 and 10,536.21

Step by Step Solution

1. Step 1: Write the proportion equation
   20,402.31 : 30,578.86 = 10,536.21 : x
2. Step 2: Convert to fraction form
   20,402.31/30,578.86 = 10,536.21/x
3. Step 3: Cross multiply
   20,402.31x = 30,578.86 × 10,536.21
4. Step 4: Simplify right side
   20,402.31x = 322,185,290.52
5. Step 5: Solve for x
   x = 322,185,290.52/20,402.31
6. Step 6: Final answer
   x = 15,791.61