Finding the Fourth Proportional to 2,112.18, 2,915.43 and 1,228.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,112.18 : 2,915.43 = 1,228.32 : x
2. Step 2: Convert to fraction form
   2,112.18/2,915.43 = 1,228.32/x
3. Step 3: Cross multiply
   2,112.18x = 2,915.43 × 1,228.32
4. Step 4: Simplify right side
   2,112.18x = 3,581,080.98
5. Step 5: Solve for x
   x = 3,581,080.98/2,112.18
6. Step 6: Final answer
   x = 1,695.44