Finding the Fourth Proportional to 20,763.30, 28,644.37 and 12,697.31

Step by Step Solution

1. Step 1: Write the proportion equation
   20,763.30 : 28,644.37 = 12,697.31 : x
2. Step 2: Convert to fraction form
   20,763.30/28,644.37 = 12,697.31/x
3. Step 3: Cross multiply
   20,763.30x = 28,644.37 × 12,697.31
4. Step 4: Simplify right side
   20,763.30x = 363,706,429.77
5. Step 5: Solve for x
   x = 363,706,429.77/20,763.30
6. Step 6: Final answer
   x = 17,516.79