Finding the Fourth Proportional to 2,799.36, 4,200.00 and 1,239.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,799.36 : 4,200.00 = 1,239.15 : x
2. Step 2: Convert to fraction form
   2,799.36/4,200.00 = 1,239.15/x
3. Step 3: Cross multiply
   2,799.36x = 4,200.00 × 1,239.15
4. Step 4: Simplify right side
   2,799.36x = 5,204,423.80
5. Step 5: Solve for x
   x = 5,204,423.80/2,799.36
6. Step 6: Final answer
   x = 1,859.15