Finding the Fourth Proportional to 12,945.36, 17,863.56 and 7,909.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,945.36 : 17,863.56 = 7,909.20 : x
2. Step 2: Convert to fraction form
   12,945.36/17,863.56 = 7,909.20/x
3. Step 3: Cross multiply
   12,945.36x = 17,863.56 × 7,909.20
4. Step 4: Simplify right side
   12,945.36x = 141,286,468.75
5. Step 5: Solve for x
   x = 141,286,468.75/12,945.36
6. Step 6: Final answer
   x = 10,914.06