Finding the Fourth Proportional to 2,216.80, 3,320.40 and 2,216.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,216.80 : 3,320.40 = 2,216.80 : x
2. Step 2: Convert to fraction form
   2,216.80/3,320.40 = 2,216.80/x
3. Step 3: Cross multiply
   2,216.80x = 3,320.40 × 2,216.80
4. Step 4: Simplify right side
   2,216.80x = 7,360,662.72
5. Step 5: Solve for x
   x = 7,360,662.72/2,216.80
6. Step 6: Final answer
   x = 3,320.40