Finding the Fourth Proportional to 13,128.63, 19,687.77 and 5,728.02

Step by Step Solution

1. Step 1: Write the proportion equation
   13,128.63 : 19,687.77 = 5,728.02 : x
2. Step 2: Convert to fraction form
   13,128.63/19,687.77 = 5,728.02/x
3. Step 3: Cross multiply
   13,128.63x = 19,687.77 × 5,728.02
4. Step 4: Simplify right side
   13,128.63x = 112,771,940.32
5. Step 5: Solve for x
   x = 112,771,940.32/13,128.63
6. Step 6: Final answer
   x = 8,589.77