Finding the Fourth Proportional to 12,912.40, 17,813.82 and 7,875.82

Step by Step Solution

1. Step 1: Write the proportion equation
   12,912.40 : 17,813.82 = 7,875.82 : x
2. Step 2: Convert to fraction form
   12,912.40/17,813.82 = 7,875.82/x
3. Step 3: Cross multiply
   12,912.40x = 17,813.82 × 7,875.82
4. Step 4: Simplify right side
   12,912.40x = 140,298,439.83
5. Step 5: Solve for x
   x = 140,298,439.83/12,912.40
6. Step 6: Final answer
   x = 10,865.40