Finding the Fourth Proportional to 9,826.80, 13,561.30 and 5,578.05

Step by Step Solution

1. Step 1: Write the proportion equation
   9,826.80 : 13,561.30 = 5,578.05 : x
2. Step 2: Convert to fraction form
   9,826.80/13,561.30 = 5,578.05/x
3. Step 3: Cross multiply
   9,826.80x = 13,561.30 × 5,578.05
4. Step 4: Simplify right side
   9,826.80x = 75,645,609.47
5. Step 5: Solve for x
   x = 75,645,609.47/9,826.80
6. Step 6: Final answer
   x = 7,697.89