Finding the Fourth Proportional to 12,661.43, 18,986.37 and 5,261.48

Step by Step Solution

1. Step 1: Write the proportion equation
   12,661.43 : 18,986.37 = 5,261.48 : x
2. Step 2: Convert to fraction form
   12,661.43/18,986.37 = 5,261.48/x
3. Step 3: Cross multiply
   12,661.43x = 18,986.37 × 5,261.48
4. Step 4: Simplify right side
   12,661.43x = 99,896,406.03
5. Step 5: Solve for x
   x = 99,896,406.03/12,661.43
6. Step 6: Final answer
   x = 7,889.82