Finding the Fourth Proportional to 20,748.39, 31,131.63 and 10,885.29

Step by Step Solution

1. Step 1: Write the proportion equation
   20,748.39 : 31,131.63 = 10,885.29 : x
2. Step 2: Convert to fraction form
   20,748.39/31,131.63 = 10,885.29/x
3. Step 3: Cross multiply
   20,748.39x = 31,131.63 × 10,885.29
4. Step 4: Simplify right side
   20,748.39x = 338,876,820.72
5. Step 5: Solve for x
   x = 338,876,820.72/20,748.39
6. Step 6: Final answer
   x = 16,332.68