Finding the Fourth Proportional to 9,411.90, 12,990.78 and 5,635.99

Step by Step Solution

1. Step 1: Write the proportion equation
   9,411.90 : 12,990.78 = 5,635.99 : x
2. Step 2: Convert to fraction form
   9,411.90/12,990.78 = 5,635.99/x
3. Step 3: Cross multiply
   9,411.90x = 12,990.78 × 5,635.99
4. Step 4: Simplify right side
   9,411.90x = 73,215,889.30
5. Step 5: Solve for x
   x = 73,215,889.30/9,411.90
6. Step 6: Final answer
   x = 7,779.08