Finding the Fourth Proportional to 21,066.82, 31,619.67 and 10,685.86

Step by Step Solution

1. Step 1: Write the proportion equation
   21,066.82 : 31,619.67 = 10,685.86 : x
2. Step 2: Convert to fraction form
   21,066.82/31,619.67 = 10,685.86/x
3. Step 3: Cross multiply
   21,066.82x = 31,619.67 × 10,685.86
4. Step 4: Simplify right side
   21,066.82x = 337,883,366.87
5. Step 5: Solve for x
   x = 337,883,366.87/21,066.82
6. Step 6: Final answer
   x = 16,038.65