Finding the Fourth Proportional to 20,928.16, 31,379.94 and 8,448.59

Step by Step Solution

1. Step 1: Write the proportion equation
   20,928.16 : 31,379.94 = 8,448.59 : x
2. Step 2: Convert to fraction form
   20,928.16/31,379.94 = 8,448.59/x
3. Step 3: Cross multiply
   20,928.16x = 31,379.94 × 8,448.59
4. Step 4: Simplify right side
   20,928.16x = 265,116,247.28
5. Step 5: Solve for x
   x = 265,116,247.28/20,928.16
6. Step 6: Final answer
   x = 12,667.92