Finding the Fourth Proportional to 12,389.81, 17,093.75 and 7,916.18

Step by Step Solution

1. Step 1: Write the proportion equation
   12,389.81 : 17,093.75 = 7,916.18 : x
2. Step 2: Convert to fraction form
   12,389.81/17,093.75 = 7,916.18/x
3. Step 3: Cross multiply
   12,389.81x = 17,093.75 × 7,916.18
4. Step 4: Simplify right side
   12,389.81x = 135,317,076.83
5. Step 5: Solve for x
   x = 135,317,076.83/12,389.81
6. Step 6: Final answer
   x = 10,921.65