Finding the Fourth Proportional to 13,687.89, 18,889.29 and 7,400.25

Step by Step Solution

1. Step 1: Write the proportion equation
   13,687.89 : 18,889.29 = 7,400.25 : x
2. Step 2: Convert to fraction form
   13,687.89/18,889.29 = 7,400.25/x
3. Step 3: Cross multiply
   13,687.89x = 18,889.29 × 7,400.25
4. Step 4: Simplify right side
   13,687.89x = 139,785,468.32
5. Step 5: Solve for x
   x = 139,785,468.32/13,687.89
6. Step 6: Final answer
   x = 10,212.35