Finding the Fourth Proportional to 2,287.07, 3,156.15 and 1,239.13

Step by Step Solution

1. Step 1: Write the proportion equation
   2,287.07 : 3,156.15 = 1,239.13 : x
2. Step 2: Convert to fraction form
   2,287.07/3,156.15 = 1,239.13/x
3. Step 3: Cross multiply
   2,287.07x = 3,156.15 × 1,239.13
4. Step 4: Simplify right side
   2,287.07x = 3,910,880.15
5. Step 5: Solve for x
   x = 3,910,880.15/2,287.07
6. Step 6: Final answer
   x = 1,710.00