Finding the Fourth Proportional to 2,515.40, 3,772.18 and 871.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,515.40 : 3,772.18 = 871.48 : x
2. Step 2: Convert to fraction form
   2,515.40/3,772.18 = 871.48/x
3. Step 3: Cross multiply
   2,515.40x = 3,772.18 × 871.48
4. Step 4: Simplify right side
   2,515.40x = 3,287,379.43
5. Step 5: Solve for x
   x = 3,287,379.43/2,515.40
6. Step 6: Final answer
   x = 1,306.90