Finding the Fourth Proportional to 21,638.72, 32,467.04 and 7,789.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,638.72 : 32,467.04 = 7,789.12 : x
2. Step 2: Convert to fraction form
   21,638.72/32,467.04 = 7,789.12/x
3. Step 3: Cross multiply
   21,638.72x = 32,467.04 × 7,789.12
4. Step 4: Simplify right side
   21,638.72x = 252,889,670.60
5. Step 5: Solve for x
   x = 252,889,670.60/21,638.72
6. Step 6: Final answer
   x = 11,686.91