Finding the Fourth Proportional to 13,196.28, 18,210.78 and 7,891.32

Step by Step Solution

1. Step 1: Write the proportion equation
   13,196.28 : 18,210.78 = 7,891.32 : x
2. Step 2: Convert to fraction form
   13,196.28/18,210.78 = 7,891.32/x
3. Step 3: Cross multiply
   13,196.28x = 18,210.78 × 7,891.32
4. Step 4: Simplify right side
   13,196.28x = 143,707,092.43
5. Step 5: Solve for x
   x = 143,707,092.43/13,196.28
6. Step 6: Final answer
   x = 10,889.97