Finding the Fourth Proportional to 2,155.71, 2,974.80 and 1,211.49

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.71 : 2,974.80 = 1,211.49 : x
2. Step 2: Convert to fraction form
   2,155.71/2,974.80 = 1,211.49/x
3. Step 3: Cross multiply
   2,155.71x = 2,974.80 × 1,211.49
4. Step 4: Simplify right side
   2,155.71x = 3,603,940.45
5. Step 5: Solve for x
   x = 3,603,940.45/2,155.71
6. Step 6: Final answer
   x = 1,671.81