Finding the Fourth Proportional to 9,411.94, 12,986.76 and 5,431.60

Step by Step Solution

1. Step 1: Write the proportion equation
   9,411.94 : 12,986.76 = 5,431.60 : x
2. Step 2: Convert to fraction form
   9,411.94/12,986.76 = 5,431.60/x
3. Step 3: Cross multiply
   9,411.94x = 12,986.76 × 5,431.60
4. Step 4: Simplify right side
   9,411.94x = 70,538,885.62
5. Step 5: Solve for x
   x = 70,538,885.62/9,411.94
6. Step 6: Final answer
   x = 7,494.62