Finding the Fourth Proportional to 2,100.80, 2,901.05 and 1,356.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,100.80 : 2,901.05 = 1,356.05 : x
2. Step 2: Convert to fraction form
   2,100.80/2,901.05 = 1,356.05/x
3. Step 3: Cross multiply
   2,100.80x = 2,901.05 × 1,356.05
4. Step 4: Simplify right side
   2,100.80x = 3,933,947.57
5. Step 5: Solve for x
   x = 3,933,947.57/2,100.80
6. Step 6: Final answer
   x = 1,872.60