Finding the Fourth Proportional to 8,471.59, 12,704.69 and 7,918.78

Step by Step Solution

1. Step 1: Write the proportion equation
   8,471.59 : 12,704.69 = 7,918.78 : x
2. Step 2: Convert to fraction form
   8,471.59/12,704.69 = 7,918.78/x
3. Step 3: Cross multiply
   8,471.59x = 12,704.69 × 7,918.78
4. Step 4: Simplify right side
   8,471.59x = 100,605,645.08
5. Step 5: Solve for x
   x = 100,605,645.08/8,471.59
6. Step 6: Final answer
   x = 11,875.65