Finding the Fourth Proportional to 9,891.81, 14,843.69 and 5,215.28

Step by Step Solution

1. Step 1: Write the proportion equation
   9,891.81 : 14,843.69 = 5,215.28 : x
2. Step 2: Convert to fraction form
   9,891.81/14,843.69 = 5,215.28/x
3. Step 3: Cross multiply
   9,891.81x = 14,843.69 × 5,215.28
4. Step 4: Simplify right side
   9,891.81x = 77,413,899.29
5. Step 5: Solve for x
   x = 77,413,899.29/9,891.81
6. Step 6: Final answer
   x = 7,826.06