Finding the Fourth Proportional to 2,221.68, 3,329.98 and 1,389.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,221.68 : 3,329.98 = 1,389.12 : x
2. Step 2: Convert to fraction form
   2,221.68/3,329.98 = 1,389.12/x
3. Step 3: Cross multiply
   2,221.68x = 3,329.98 × 1,389.12
4. Step 4: Simplify right side
   2,221.68x = 4,625,741.82
5. Step 5: Solve for x
   x = 4,625,741.82/2,221.68
6. Step 6: Final answer
   x = 2,082.09