Finding the Fourth Proportional to 21,870.65, 30,182.46 and 12,311.16

Step by Step Solution

1. Step 1: Write the proportion equation
   21,870.65 : 30,182.46 = 12,311.16 : x
2. Step 2: Convert to fraction form
   21,870.65/30,182.46 = 12,311.16/x
3. Step 3: Cross multiply
   21,870.65x = 30,182.46 × 12,311.16
4. Step 4: Simplify right side
   21,870.65x = 371,580,934.90
5. Step 5: Solve for x
   x = 371,580,934.90/21,870.65
6. Step 6: Final answer
   x = 16,989.93