Finding the Fourth Proportional to 12,911.80, 17,810.54 and 7,935.16

Step by Step Solution

1. Step 1: Write the proportion equation
   12,911.80 : 17,810.54 = 7,935.16 : x
2. Step 2: Convert to fraction form
   12,911.80/17,810.54 = 7,935.16/x
3. Step 3: Cross multiply
   12,911.80x = 17,810.54 × 7,935.16
4. Step 4: Simplify right side
   12,911.80x = 141,329,484.59
5. Step 5: Solve for x
   x = 141,329,484.59/12,911.80
6. Step 6: Final answer
   x = 10,945.76