Finding the Fourth Proportional to 20,738.72, 28,607.52 and 12,779.36

Step by Step Solution

1. Step 1: Write the proportion equation
   20,738.72 : 28,607.52 = 12,779.36 : x
2. Step 2: Convert to fraction form
   20,738.72/28,607.52 = 12,779.36/x
3. Step 3: Cross multiply
   20,738.72x = 28,607.52 × 12,779.36
4. Step 4: Simplify right side
   20,738.72x = 365,585,796.79
5. Step 5: Solve for x
   x = 365,585,796.79/20,738.72
6. Step 6: Final answer
   x = 17,628.18