Finding the Fourth Proportional to 2,616.04, 3,920.22 and 1,315.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,616.04 : 3,920.22 = 1,315.72 : x
2. Step 2: Convert to fraction form
   2,616.04/3,920.22 = 1,315.72/x
3. Step 3: Cross multiply
   2,616.04x = 3,920.22 × 1,315.72
4. Step 4: Simplify right side
   2,616.04x = 5,157,911.86
5. Step 5: Solve for x
   x = 5,157,911.86/2,616.04
6. Step 6: Final answer
   x = 1,971.65