Finding the Fourth Proportional to 2,215.72, 3,323.63 and 1,391.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,215.72 : 3,323.63 = 1,391.50 : x
2. Step 2: Convert to fraction form
   2,215.72/3,323.63 = 1,391.50/x
3. Step 3: Cross multiply
   2,215.72x = 3,323.63 × 1,391.50
4. Step 4: Simplify right side
   2,215.72x = 4,624,831.15
5. Step 5: Solve for x
   x = 4,624,831.15/2,215.72
6. Step 6: Final answer
   x = 2,087.28