Finding the Fourth Proportional to 2,145.39, 2,960.61 and 1,213.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,145.39 : 2,960.61 = 1,213.89 : x
2. Step 2: Convert to fraction form
   2,145.39/2,960.61 = 1,213.89/x
3. Step 3: Cross multiply
   2,145.39x = 2,960.61 × 1,213.89
4. Step 4: Simplify right side
   2,145.39x = 3,593,854.87
5. Step 5: Solve for x
   x = 3,593,854.87/2,145.39
6. Step 6: Final answer
   x = 1,675.15