Finding the Fourth Proportional to 13,689.51, 18,891.52 and 7,401.88

Step by Step Solution

1. Step 1: Write the proportion equation
   13,689.51 : 18,891.52 = 7,401.88 : x
2. Step 2: Convert to fraction form
   13,689.51/18,891.52 = 7,401.88/x
3. Step 3: Cross multiply
   13,689.51x = 18,891.52 × 7,401.88
4. Step 4: Simplify right side
   13,689.51x = 139,832,769.17
5. Step 5: Solve for x
   x = 139,832,769.17/13,689.51
6. Step 6: Final answer
   x = 10,214.60