Finding the Fourth Proportional to 9,411.12, 12,986.82 and 5,377.80

Step by Step Solution

1. Step 1: Write the proportion equation
   9,411.12 : 12,986.82 = 5,377.80 : x
2. Step 2: Convert to fraction form
   9,411.12/12,986.82 = 5,377.80/x
3. Step 3: Cross multiply
   9,411.12x = 12,986.82 × 5,377.80
4. Step 4: Simplify right side
   9,411.12x = 69,840,520.60
5. Step 5: Solve for x
   x = 69,840,520.60/9,411.12
6. Step 6: Final answer
   x = 7,421.06