Finding the Fourth Proportional to 13,728.51, 18,945.35 and 7,440.89

Step by Step Solution

1. Step 1: Write the proportion equation
   13,728.51 : 18,945.35 = 7,440.89 : x
2. Step 2: Convert to fraction form
   13,728.51/18,945.35 = 7,440.89/x
3. Step 3: Cross multiply
   13,728.51x = 18,945.35 × 7,440.89
4. Step 4: Simplify right side
   13,728.51x = 140,970,133.43
5. Step 5: Solve for x
   x = 140,970,133.43/13,728.51
6. Step 6: Final answer
   x = 10,268.42