Finding the Fourth Proportional to 10,851.72, 16,358.91 and 10,128.38

Step by Step Solution

1. Step 1: Write the proportion equation
   10,851.72 : 16,358.91 = 10,128.38 : x
2. Step 2: Convert to fraction form
   10,851.72/16,358.91 = 10,128.38/x
3. Step 3: Cross multiply
   10,851.72x = 16,358.91 × 10,128.38
4. Step 4: Simplify right side
   10,851.72x = 165,689,264.72
5. Step 5: Solve for x
   x = 165,689,264.72/10,851.72
6. Step 6: Final answer
   x = 15,268.48