Finding the Fourth Proportional to 20,859.94, 28,781.76 and 12,683.31

Step by Step Solution

1. Step 1: Write the proportion equation
   20,859.94 : 28,781.76 = 12,683.31 : x
2. Step 2: Convert to fraction form
   20,859.94/28,781.76 = 12,683.31/x
3. Step 3: Cross multiply
   20,859.94x = 28,781.76 × 12,683.31
4. Step 4: Simplify right side
   20,859.94x = 365,047,984.43
5. Step 5: Solve for x
   x = 365,047,984.43/20,859.94
6. Step 6: Final answer
   x = 17,499.95