Finding the Fourth Proportional to 2,139.41, 3,206.46 and 1,212.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.41 : 3,206.46 = 1,212.15 : x
2. Step 2: Convert to fraction form
   2,139.41/3,206.46 = 1,212.15/x
3. Step 3: Cross multiply
   2,139.41x = 3,206.46 × 1,212.15
4. Step 4: Simplify right side
   2,139.41x = 3,886,716.23
5. Step 5: Solve for x
   x = 3,886,716.23/2,139.41
6. Step 6: Final answer
   x = 1,816.73