Finding the Fourth Proportional to 2,113.40, 3,171.45 and 880.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,113.40 : 3,171.45 = 880.72 : x
2. Step 2: Convert to fraction form
   2,113.40/3,171.45 = 880.72/x
3. Step 3: Cross multiply
   2,113.40x = 3,171.45 × 880.72
4. Step 4: Simplify right side
   2,113.40x = 2,793,143.59
5. Step 5: Solve for x
   x = 2,793,143.59/2,113.40
6. Step 6: Final answer
   x = 1,321.64