Finding the Fourth Proportional to 2,315.40, 3,474.72 and 2,111.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,315.40 : 3,474.72 = 2,111.28 : x
2. Step 2: Convert to fraction form
   2,315.40/3,474.72 = 2,111.28/x
3. Step 3: Cross multiply
   2,315.40x = 3,474.72 × 2,111.28
4. Step 4: Simplify right side
   2,315.40x = 7,336,106.84
5. Step 5: Solve for x
   x = 7,336,106.84/2,315.40
6. Step 6: Final answer
   x = 3,168.40