Finding the Fourth Proportional to 21,868.68, 30,168.54 and 12,910.08

Step by Step Solution

1. Step 1: Write the proportion equation
   21,868.68 : 30,168.54 = 12,910.08 : x
2. Step 2: Convert to fraction form
   21,868.68/30,168.54 = 12,910.08/x
3. Step 3: Cross multiply
   21,868.68x = 30,168.54 × 12,910.08
4. Step 4: Simplify right side
   21,868.68x = 389,478,264.88
5. Step 5: Solve for x
   x = 389,478,264.88/21,868.68
6. Step 6: Final answer
   x = 17,809.87