Finding the Fourth Proportional to 9,415.83, 12,994.25 and 5,639.61

Step by Step Solution

1. Step 1: Write the proportion equation
   9,415.83 : 12,994.25 = 5,639.61 : x
2. Step 2: Convert to fraction form
   9,415.83/12,994.25 = 5,639.61/x
3. Step 3: Cross multiply
   9,415.83x = 12,994.25 × 5,639.61
4. Step 4: Simplify right side
   9,415.83x = 73,282,502.24
5. Step 5: Solve for x
   x = 73,282,502.24/9,415.83
6. Step 6: Final answer
   x = 7,782.90