Finding the Fourth Proportional to 21,111.55, 31,672.01 and 7,964.03

Step by Step Solution

1. Step 1: Write the proportion equation
   21,111.55 : 31,672.01 = 7,964.03 : x
2. Step 2: Convert to fraction form
   21,111.55/31,672.01 = 7,964.03/x
3. Step 3: Cross multiply
   21,111.55x = 31,672.01 × 7,964.03
4. Step 4: Simplify right side
   21,111.55x = 252,236,936.89
5. Step 5: Solve for x
   x = 252,236,936.89/21,111.55
6. Step 6: Final answer
   x = 11,947.82