Finding the Fourth Proportional to 21,799.40, 30,084.15 and 12,847.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,799.40 : 30,084.15 = 12,847.28 : x
2. Step 2: Convert to fraction form
   21,799.40/30,084.15 = 12,847.28/x
3. Step 3: Cross multiply
   21,799.40x = 30,084.15 × 12,847.28
4. Step 4: Simplify right side
   21,799.40x = 386,499,498.61
5. Step 5: Solve for x
   x = 386,499,498.61/21,799.40
6. Step 6: Final answer
   x = 17,729.82