Finding the Fourth Proportional to 12,390.21, 18,588.06 and 5,816.48

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390.21 : 18,588.06 = 5,816.48 : x
2. Step 2: Convert to fraction form
   12,390.21/18,588.06 = 5,816.48/x
3. Step 3: Cross multiply
   12,390.21x = 18,588.06 × 5,816.48
4. Step 4: Simplify right side
   12,390.21x = 108,116,986.29
5. Step 5: Solve for x
   x = 108,116,986.29/12,390.21
6. Step 6: Final answer
   x = 8,726.00