Finding the Fourth Proportional to 2,139.39, 3,209.02 and 1,620.37

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.39 : 3,209.02 = 1,620.37 : x
2. Step 2: Convert to fraction form
   2,139.39/3,209.02 = 1,620.37/x
3. Step 3: Cross multiply
   2,139.39x = 3,209.02 × 1,620.37
4. Step 4: Simplify right side
   2,139.39x = 5,199,816.72
5. Step 5: Solve for x
   x = 5,199,816.72/2,139.39
6. Step 6: Final answer
   x = 2,430.52