Finding the Fourth Proportional to 8,764.64, 13,139.15 and 3,216.71

Step by Step Solution

1. Step 1: Write the proportion equation
   8,764.64 : 13,139.15 = 3,216.71 : x
2. Step 2: Convert to fraction form
   8,764.64/13,139.15 = 3,216.71/x
3. Step 3: Cross multiply
   8,764.64x = 13,139.15 × 3,216.71
4. Step 4: Simplify right side
   8,764.64x = 42,264,769.50
5. Step 5: Solve for x
   x = 42,264,769.50/8,764.64
6. Step 6: Final answer
   x = 4,822.19