Finding the Fourth Proportional to 9,409.10, 12,986.25 and 5,429.66

Step by Step Solution

1. Step 1: Write the proportion equation
   9,409.10 : 12,986.25 = 5,429.66 : x
2. Step 2: Convert to fraction form
   9,409.10/12,986.25 = 5,429.66/x
3. Step 3: Cross multiply
   9,409.10x = 12,986.25 × 5,429.66
4. Step 4: Simplify right side
   9,409.10x = 70,510,922.18
5. Step 5: Solve for x
   x = 70,510,922.18/9,409.10
6. Step 6: Final answer
   x = 7,493.91