Finding the Fourth Proportional to 20,784.84, 31,146.54 and 12,469.32

Step by Step Solution

1. Step 1: Write the proportion equation
   20,784.84 : 31,146.54 = 12,469.32 : x
2. Step 2: Convert to fraction form
   20,784.84/31,146.54 = 12,469.32/x
3. Step 3: Cross multiply
   20,784.84x = 31,146.54 × 12,469.32
4. Step 4: Simplify right side
   20,784.84x = 388,376,174.15
5. Step 5: Solve for x
   x = 388,376,174.15/20,784.84
6. Step 6: Final answer
   x = 18,685.55