Finding the Fourth Proportional to 2,615.29, 3,920.47 and 971.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,615.29 : 3,920.47 = 971.39 : x
2. Step 2: Convert to fraction form
   2,615.29/3,920.47 = 971.39/x
3. Step 3: Cross multiply
   2,615.29x = 3,920.47 × 971.39
4. Step 4: Simplify right side
   2,615.29x = 3,808,312.73
5. Step 5: Solve for x
   x = 3,808,312.73/2,615.29
6. Step 6: Final answer
   x = 1,456.17