Finding the Fourth Proportional to 21,007.31, 28,990.71 and 11,576.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,007.31 : 28,990.71 = 11,576.48 : x
2. Step 2: Convert to fraction form
   21,007.31/28,990.71 = 11,576.48/x
3. Step 3: Cross multiply
   21,007.31x = 28,990.71 × 11,576.48
4. Step 4: Simplify right side
   21,007.31x = 335,610,446.98
5. Step 5: Solve for x
   x = 335,610,446.98/21,007.31
6. Step 6: Final answer
   x = 15,975.89