Finding the Fourth Proportional to 9,915.12, 14,879.76 and 3,912.12

Step by Step Solution

1. Step 1: Write the proportion equation
   9,915.12 : 14,879.76 = 3,912.12 : x
2. Step 2: Convert to fraction form
   9,915.12/14,879.76 = 3,912.12/x
3. Step 3: Cross multiply
   9,915.12x = 14,879.76 × 3,912.12
4. Step 4: Simplify right side
   9,915.12x = 58,211,406.69
5. Step 5: Solve for x
   x = 58,211,406.69/9,915.12
6. Step 6: Final answer
   x = 5,870.97