Finding the Fourth Proportional to 2,160.74, 2,981.83 and 1,216.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,160.74 : 2,981.83 = 1,216.55 : x
2. Step 2: Convert to fraction form
   2,160.74/2,981.83 = 1,216.55/x
3. Step 3: Cross multiply
   2,160.74x = 2,981.83 × 1,216.55
4. Step 4: Simplify right side
   2,160.74x = 3,627,545.29
5. Step 5: Solve for x
   x = 3,627,545.29/2,160.74
6. Step 6: Final answer
   x = 1,678.84