Finding the Fourth Proportional to 2,626.47, 3,939.91 and 871.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,626.47 : 3,939.91 = 871.40 : x
2. Step 2: Convert to fraction form
   2,626.47/3,939.91 = 871.40/x
3. Step 3: Cross multiply
   2,626.47x = 3,939.91 × 871.40
4. Step 4: Simplify right side
   2,626.47x = 3,433,245.25
5. Step 5: Solve for x
   x = 3,433,245.25/2,626.47
6. Step 6: Final answer
   x = 1,307.17