Finding the Fourth Proportional to 12,945.98, 17,866.40 and 7,911.16

Step by Step Solution

1. Step 1: Write the proportion equation
   12,945.98 : 17,866.40 = 7,911.16 : x
2. Step 2: Convert to fraction form
   12,945.98/17,866.40 = 7,911.16/x
3. Step 3: Cross multiply
   12,945.98x = 17,866.40 × 7,911.16
4. Step 4: Simplify right side
   12,945.98x = 141,343,949.02
5. Step 5: Solve for x
   x = 141,343,949.02/12,945.98
6. Step 6: Final answer
   x = 10,917.98