Finding the Fourth Proportional to 11,154.71, 15,389.25 and 7,121.69

Step by Step Solution

1. Step 1: Write the proportion equation
   11,154.71 : 15,389.25 = 7,121.69 : x
2. Step 2: Convert to fraction form
   11,154.71/15,389.25 = 7,121.69/x
3. Step 3: Cross multiply
   11,154.71x = 15,389.25 × 7,121.69
4. Step 4: Simplify right side
   11,154.71x = 109,597,390.89
5. Step 5: Solve for x
   x = 109,597,390.89/11,154.71
6. Step 6: Final answer
   x = 9,825.21