Finding the Fourth Proportional to 8,680.29, 11,978.73 and 5,145.18

Step by Step Solution

1. Step 1: Write the proportion equation
   8,680.29 : 11,978.73 = 5,145.18 : x
2. Step 2: Convert to fraction form
   8,680.29/11,978.73 = 5,145.18/x
3. Step 3: Cross multiply
   8,680.29x = 11,978.73 × 5,145.18
4. Step 4: Simplify right side
   8,680.29x = 61,632,722.02
5. Step 5: Solve for x
   x = 61,632,722.02/8,680.29
6. Step 6: Final answer
   x = 7,100.31