Finding the Fourth Proportional to 21,109.68, 31,672.89 and 7,965.54

Step by Step Solution

1. Step 1: Write the proportion equation
   21,109.68 : 31,672.89 = 7,965.54 : x
2. Step 2: Convert to fraction form
   21,109.68/31,672.89 = 7,965.54/x
3. Step 3: Cross multiply
   21,109.68x = 31,672.89 × 7,965.54
4. Step 4: Simplify right side
   21,109.68x = 252,291,672.21
5. Step 5: Solve for x
   x = 252,291,672.21/21,109.68
6. Step 6: Final answer
   x = 11,951.47