Finding the Fourth Proportional to 21,799.60, 30,086.82 and 12,850

Step by Step Solution

1. Step 1: Write the proportion equation
   21,799.60 : 30,086.82 = 12,850 : x
2. Step 2: Convert to fraction form
   21,799.60/30,086.82 = 12,850/x
3. Step 3: Cross multiply
   21,799.60x = 30,086.82 × 12,850
4. Step 4: Simplify right side
   21,799.60x = 386,615,637
5. Step 5: Solve for x
   x = 386,615,637/21,799.60
6. Step 6: Final answer
   x = 17,734.99