Finding the Fourth Proportional to 21,805.65, 30,088.17 and 12,851.91

Step by Step Solution

1. Step 1: Write the proportion equation
   21,805.65 : 30,088.17 = 12,851.91 : x
2. Step 2: Convert to fraction form
   21,805.65/30,088.17 = 12,851.91/x
3. Step 3: Cross multiply
   21,805.65x = 30,088.17 × 12,851.91
4. Step 4: Simplify right side
   21,805.65x = 386,690,452.90
5. Step 5: Solve for x
   x = 386,690,452.90/21,805.65
6. Step 6: Final answer
   x = 17,733.50