Finding the Fourth Proportional to 1,909.68, 2,859.40 and 1,086.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,909.68 : 2,859.40 = 1,086.72 : x
2. Step 2: Convert to fraction form
   1,909.68/2,859.40 = 1,086.72/x
3. Step 3: Cross multiply
   1,909.68x = 2,859.40 × 1,086.72
4. Step 4: Simplify right side
   1,909.68x = 3,107,367.17
5. Step 5: Solve for x
   x = 3,107,367.17/1,909.68
6. Step 6: Final answer
   x = 1,627.17