Finding the Fourth Proportional to 2,105.80, 3,162.30 and 1,378.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,105.80 : 3,162.30 = 1,378.60 : x
2. Step 2: Convert to fraction form
   2,105.80/3,162.30 = 1,378.60/x
3. Step 3: Cross multiply
   2,105.80x = 3,162.30 × 1,378.60
4. Step 4: Simplify right side
   2,105.80x = 4,359,546.78
5. Step 5: Solve for x
   x = 4,359,546.78/2,105.80
6. Step 6: Final answer
   x = 2,070.26