Finding the Fourth Proportional to 2,641.80, 3,956.76 and 1,945.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,641.80 : 3,956.76 = 1,945.20 : x
2. Step 2: Convert to fraction form
   2,641.80/3,956.76 = 1,945.20/x
3. Step 3: Cross multiply
   2,641.80x = 3,956.76 × 1,945.20
4. Step 4: Simplify right side
   2,641.80x = 7,696,689.55
5. Step 5: Solve for x
   x = 7,696,689.55/2,641.80
6. Step 6: Final answer
   x = 2,913.43