Finding the Fourth Proportional to 2,287.50, 3,156.75 and 1,239.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,287.50 : 3,156.75 = 1,239.57 : x
2. Step 2: Convert to fraction form
   2,287.50/3,156.75 = 1,239.57/x
3. Step 3: Cross multiply
   2,287.50x = 3,156.75 × 1,239.57
4. Step 4: Simplify right side
   2,287.50x = 3,913,012.60
5. Step 5: Solve for x
   x = 3,913,012.60/2,287.50
6. Step 6: Final answer
   x = 1,710.61