Finding the Fourth Proportional to 21,870.93, 30,179.16 and 12,309.63

Step by Step Solution

1. Step 1: Write the proportion equation
   21,870.93 : 30,179.16 = 12,309.63 : x
2. Step 2: Convert to fraction form
   21,870.93/30,179.16 = 12,309.63/x
3. Step 3: Cross multiply
   21,870.93x = 30,179.16 × 12,309.63
4. Step 4: Simplify right side
   21,870.93x = 371,494,293.31
5. Step 5: Solve for x
   x = 371,494,293.31/21,870.93
6. Step 6: Final answer
   x = 16,985.76